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Evaluating the Potential of Oleaginous Yeasts as Feedstock for Biodiesel Production

Mukhtar H, Suliman SM, Shabbir A, Mumtaz MW, Rashid U, Rahimuddin SA

Protein Pept Lett, 2018;25(2):195-201.
PMID: 29359654 DOI: 10.2174/0929866525666180122112805

BACKGROUND: Lipid-producing microorganisms, said to be oleaginous have been recognized since several years. We had investigated the effects of medium components and culturing situations on cell growth and lipid accumulation of oleaginous yeasts which were analytically examined so as to enhance lipid yield for biodiesel production.
OBJECTIVE: The main objective of this study was to explore oleaginous yeast, Yarrowia lipolytica isolated from soil and optimization of culture conditions and medium components to obtained better quality microbial oil for biodiesel production.
METHODS: Fifty yeast strains were isolated from soil from different regions of Lahore and eleven of them were selected for oil production. The isolated yeast colonies were screened to further check their lipid producing capabilities by the qualitative analysis. Five yeast strains were designated as oleaginous because they produced more than 16% of oil based on their biomass. To estimate the total lipid content of yeast cells, the extraction of lipids was done by performing the procedure proposed by Bligh and Dyer. The transesterification of yeast oils was performed by using different methods. There were three different strategies customized to transesterifying microbial oil using base catalyzed transesterification, acid catalyzed transesterification and enzyme-based transesterification. After completion of transesterification, sample was used for fatty acid methyl esters (FAMEs) were analyzed by gas-chromatograph with ionization detector type MS.
RESULTS: The isolate IIB-10 identified as Yarrowia lipolytica produced maximum amount of lipids i.e. 22.8%. More amount of biomass was obtained when cane molasses was utilized as carbon source where it produced 29.4 g/L of biomass while sucrose and lactose were not utilized by IIB-10 and no biomass was obtained. Similarly, meat extracts showed best results when it was used as nitrogen source because it resulted in 35.8 g/L biomass of Yarrowia lipolytica IIB-10. The culturing conditions like size of inoculum, effect of pH and time of incubation were also studied. The 10% of inoculum size produced 25.4 g/L biomass at 120 h incubation time, while the pH 7 was the optimum pH at which 24.8 g/L biomass was produced by Yarrowia lipolytica IIB-10. GC-MS analysis showed that biodiesel produced by transesterification contained similar fatty acids as found in vegetable oil for this reason it is widely accepted feedstock for biodiesel production.
CONCLUSION: The analysis of fatty acids methyl esters showed the similar composition of microbial oil as in vegetable oils and high amount of methyl esters were obtained after transesterification. Therefore, potentially oleaginous yeast could be used to generate a large amount of lipids for biodiesel production that will be the better substitute of petroleum-based diesel and will also control the environmental pollution.

Matched MeSH terms: Soil
Historical atmospheric pollution trends in Southeast Asia inferred from lake sediment records

Engels S, Fong LSRZ, Chen Q, Leng MJ, McGowan S, Idris M, et al.

Environ Pollut, 2018 Apr;235:907-917.
PMID: 29353806 DOI: 10.1016/j.envpol.2018.01.007

Fossil fuel combustion leads to increased levels of air pollution, which negatively affects human health as well as the environment. Documented data for Southeast Asia (SEA) show a strong increase in fossil fuel consumption since 1980, but information on coal and oil combustion before 1980 is not widely available. Spheroidal carbonaceous particles (SCPs) and heavy metals, such as mercury (Hg), are emitted as by-products of fossil fuel combustion and may accumulate in sediments following atmospheric fallout. Here we use sediment SCP and Hg records from several freshwater lentic ecosystems in SEA (Malaysia, Philippines, Singapore) to reconstruct long-term, region-wide variations in levels of these two key atmospheric pollution indicators. The age-depth models of Philippine sediment cores do not reach back far enough to date first SCP presence, but single SCP occurrences are first observed between 1925 and 1950 for a Malaysian site. Increasing SCP flux is observed at our sites from 1960 onward, although individual sites show minor differences in trends. SCP fluxes show a general decline after 2000 at each of our study sites. While the records show broadly similar temporal trends across SEA, absolute SCP fluxes differ between sites, with a record from Malaysia showing SCP fluxes that are two orders of magnitude lower than records from the Philippines. Similar trends in records from China and Japan represent the emergence of atmospheric pollution as a broadly-based inter-region environmental problem during the 20th century. Hg fluxes were relatively stable from the second half of the 20th century onward. As catchment soils are also contaminated with atmospheric Hg, future soil erosion can be expected to lead to enhanced Hg flux into surface waters.

Matched MeSH terms: Soil
Can treatment of Brachiaria decumbens (signal grass) improve its utilisation in the diet in small ruminants?-a review

Chung ELT, Predith M, Nobilly F, Samsudin AA, Jesse FFA, Loh TC

Trop Anim Health Prod, 2018 Jun 20.
PMID: 29926360 DOI: 10.1007/s11250-018-1641-4

Brachiaria decumbens is an extremely productive tropical grass due to its aggressive growth habit and its adaptation to a varied range of soil types and environments. As a result of the vast availability, treated B. decumbens demonstrates as a promising local material that could be utilised as an improved diet for sheep and goats. Despite the fact that the grass significantly increases weight gains in grazing farm animals, there were many reports of general ill-thrift and sporadic outbreaks of photosensitivity in livestock due to the toxic compound of steroidal saponin found in B. decumbens. Ensiling and haymaking were found to be effective in removing toxin and undesirable compounds in the grass. Biological treatments using urea, activated charcoal, polyethylene glycol, and effective microorganisms were found to be useful in anti-nutritional factor deactivation and improving the nutritive values of feedstuffs. Besides, oral administration of phenobarbitone showed some degree of protection in sheep that fed on B. decumbens pasture. In this review, we aim to determine the effect of B. decumbens toxicity and possible treatment methods on the grass to be used as an improved diet for small ruminant.

Matched MeSH terms: Soil
Fulltext Antioxidative Potential of a Streptomyces sp. MUM292 Isolated from Mangrove Soil

Tan LT, Chan KG, Chan CK, Khan TM, Lee LH, Goh BH

Biomed Res Int, 2018;2018:4823126.
PMID: 29805975 DOI: 10.1155/2018/4823126

Mangrove derived microorganisms constitute a rich bioresource for bioprospecting of bioactive natural products. This study explored the antioxidant potentials of Streptomyces bacteria derived from mangrove soil. Based on 16S rRNA phylogenetic analysis, strain MUM292 was identified as the genus Streptomyces. Strain MUM292 showed the highest 16S rRNA gene sequence similarity of 99.54% with S. griseoruber NBRC12873T. Furthermore, strain MUM292 was also characterized and showed phenotypic characteristics consistent with Streptomyces bacteria. Fermentation and extraction were performed to obtain the MUM292 extract containing the secondary metabolites of strain MUM292. The extract displayed promising antioxidant activities, including DPPH, ABTS, and superoxide radical scavenging and also metal-chelating activities. The process of lipid peroxidation in lipid-rich product was also retarded by MUM292 extract and resulted in reduced MDA production. The potential bioactive constituents of MUM292 extract were investigated using GC-MS and preliminary detection showed the presence of pyrazine, pyrrole, cyclic dipeptides, and phenolic compound in MUM292 extract. This work demonstrates that Streptomyces MUM292 can be a potential antioxidant resource for food and pharmaceutical industries.

Matched MeSH terms: Soil Microbiology
Encapsulation of Bacillus salmalaya 139SI using double coating biopolymer technique

Vejan P, Abdullah R, Khadiran T, Ismail S

Lett Appl Microbiol, 2019 Jan;68(1):56-63.
PMID: 30339728 DOI: 10.1111/lam.13088

Sustainable crop production for a rapidly growing human population is one of the current challenges faced by the agricultural sector. However, many of the chemical agents used in agriculture can be hazardous to humans, non-targeted organism and environment. Plant growth promoting rhizobacteria have demonstrated a role in promoting plant growth and health under various stress conditions including disease. Unfortunately, bacterial viability degrades due to temperature and other environmental factors (Bashan et al., Plant Soil 378: 1-33, 2014). Encapsulation of bacteria into core-shell biopolymers is one of the promising techniques to overcome the problem. This study deals with the encapsulation of Bacillus salmalaya 139SI using simple double coating biopolymer technique which consist of brown rice protein/alginate and 0·5% low molecular weight chitosan of pH 4 and 6. The influence of biopolymer to bacteria mass ratio and the chitosan pH on the encapsulation process, physic-chemical, morphology and bioactivity properties of encapsulated B. salmalaya 139SI have been studied systematically. Based on the analysis of physico-chemical, morphology and bioactivity properties, B. salmalaya 139S1 encapsulated using double coating encapsulation technology has promising viability pre- and postfreeze-drying with excellent encapsulation yields of 99·7 and 89·3% respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: The need of a simple yet effective way of encapsulating plant growth promoting rhizobacteria is crucial to further improve their benefits to global sustainable agriculture practice. Effective encapsulation allows for protection, controlled release and function of the micro-organism, as well as providing a longer shelf life for the product. This research report offers an innovative yet simple way of encapsulating using double coating technology with environmentally friendly biopolymers that could degrade and provide nutrients when in soil. Importantly, the bioactivity of the bacteria is maintained upon encapsulation.

Matched MeSH terms: Soil
Fulltext Isolation and characterization of a 2,4-dinitrophenol-degrading bacterium

Noor Suffiah Md. Zin, Siti Nadzirah Padrilah, Mohd Fadhil Abd. Rahman, Koh, Sim Han, Ariff Khalid, Mohd. Yunus Shukor

Bioremediation Science and Technology Research, 2016;4(2):28-33.
MyJurnal

2,4-dinitrophenol (2,4-DNP) is utilized in the production of wood preservatives, dyes, and also
as a pesticide. Human acute (short-term) exposure to 2,4-DNP in humans by means of oral
exposure are nausea or vomiting, sweating, headaches, dizziness, and weight reduction. Thus, the
removal of this compound is highly sought. A 2,4-DNP-degrading bacterium (isolate 1) was
isolated from a sample soil from Terengganu. This bacterium (isolate 1) was characterized as a
rod Gram positive, non-sporulated, and non-motile bacterium. The bacterium is oxidase negative
and had catalase positive activity and was able to grow aerobically on 2,4-dinitrophenol as the
sole carbon source. This bacterium showed maximal growth on 2,4-DNP at the temperature
optimum of 30 oC, pH 5.0 and was tolerant to 2,4-DNP concentration of up to 0.5 mM (0.092
g/L). This bacterium prefers to use urea as the nitrogen source in addition to yeast extract for
mineral source and vitamin precursors.

Matched MeSH terms: Soil
Fulltext Isolation and characterization of a heavy metal-reducing Pseudomonas sp. strain Dr.Y Kertih with the ability to assimilate phenol and diesel

Veeraswamy Kesavan, Abdulrasheed Mansur, Mohd Syahmi Ramzi Salihan, Rahman, M.F., Suhaili, Zarizal, Shukor, M.Y.

Bioremediation Science and Technology Research, 2018;6(1):14-22.
MyJurnal

The indiscriminate released of heavy metals and xenobiotics into soils and aquatic bodies
severely alter soil organisms and the ecosystem. The isolation of xenobiotics degrading
microorganisms is cost-effective and naturally pleasant approach. Lately, the toxicological effect
of molybdenum to the spermatogenesis of several organisms has been record. This present study
is aimed at the isolation and characterization of a bacterium capable of converting molybdenum
to the colloidal molybdenum blue. Bacteria characterization was performed in a microplate
format using resting cells. Thus, the reduction process can be employed as a device for
molybdenum bioremediation. The results of the study revealed an optimum reduction at pH
between 6.0 and 6.3 and temperatures of between 25 and 40 oC. Similarly, it was also observed
that a phosphate concentration not greater than 5.0 mM and a sodium molybdate concentration
at 20 mM was required for reduction. Glucose was observed as the best carbon source to support
reduction. Following the scanning of molybdenum blue, it revealed an absorption spectrum
indicating the characteristics of molybdenum blue as a reduced phosphomolybdate. Molybdenum
reduction is inhibited by heavy metals like silver, lead, arsenic and mercury. Furthermore, the
ability of the bacterium (Pseudomonas sp. strain Dr.Y Kertih) to utilize several organic
xenobiotics such as phenol, acrylamide, nicotinamide, acetamide, iodoacetamide, propionamide,
acetamide, sodium dodecyl sulfate (SDS) and diesel as electron donor sources for aiding
reduction or as carbon sources for growth was also examined. Finding showed that none was
capable of aiding molybdenum reduction, however the bacterium was capable of growing on both
diesel and phenol as carbon sources. GC analysis was used to confirmed diesel degradation.

Matched MeSH terms: Soil
First Report of Damping-Off on Basella rubra Caused by Rhizoctonia solani Anastomosis Group 4 in Florida

Liao X, Fu Y, Zhang S, Duan YP

Plant Dis, 2012 Feb;96(2):288.
PMID: 30731824 DOI: 10.1094/PDIS-08-11-0639

Indian spinach (Basella rubra L.) is a red stem species of Basella that is cultivated worldwide as an ornamental and the aerial parts are also consumed as a vegetable. In May of 2011, symptoms of damping-off were observed on approximately 10% of the plants at the stem base around the soil line of seedlings in a greenhouse in Homestead, FL. Lesions were initially water soaked, grayish to dark brown, irregular in shape, and sunken in appearance on large plants, causing the infected seedlings to collapse and eventually die. Symptomatic stem tissue was surface sterilized with 0.6% sodium hypochlorite, rinsed in sterile distilled water, air dried, and plated on potato dextrose agar (PDA). Plates were incubated at 25°C in darkness for 3 to 5 days. A fungus was isolated in all six isolations from symptomatic tissues on PDA. Fungal colonies on PDA were light gray to brown with abundant growth of mycelia, and the hyphae tended to branch at right angles when examined under a microscope. A septum was always present in the branch of hyphae near the originating point and a slight constriction at the branch was observed. Neither conidia nor conidiophores were found from the cultures on PDA. The characteristics of hyphae, especially the right angle branching of mycelia, indicate close similarity to those of Rhizoctonia solani (2,3). The internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced (GenBank Accession No. JN545836). Subsequent database searches by the BLASTN program indicated that the resulting sequence had a 100% identity over 472 bp with the corresponding gene sequence of R. solani anastomosis group (AG) 4 (GenBank Accession No. JF701752.1), a fungal pathogen reported to cause damping-off on many crops. Pathogenicity was confirmed through inoculation of healthy India spinach plants with the hyphae of isolates. Four 4-week-old plants were inoculated with the isolates by placing a 5-mm PDA plug of mycelia at the stem base and covering with a thin layer of the soil. Another four plants treated with sterile PDA served as a control. After inoculation, the plants were covered with plastic bags for 24 h and maintained in a greenhouse with ambient conditions. Four days after inoculation, water-soaked, brown lesions, identical to the symptoms described above, were observed on the stem base of all inoculated plants, whereas no symptoms developed on the control plants. The fungus was isolated from affected stem samples, and the identity was confirmed by microscopic appearance of the hyphae and sequencing the ITS1/ITS4 intergenic spacer region, fulfilling Koch's postulates. This pathogenicity test was conducted twice. R. solani has been reported to cause damping-off of B. rubra in Ghana (1) and Malaysia (4). To our knowledge, this is the first report of damping-off caused by R. solani AG-4 on Indian spinach in Florida and the United States. With the increased interest in producing Asian vegetables for food and ornamental purposes, the occurrence of damping-off on Indian spinach needs to be taken into account when designing programs for disease management in Florida. References: (1) H. A. Dade. XXIX. Bull. Misc. Inform. 6:205, 1940. (2) J. R. Parmeter et al. Phytopathology 57:218, 1967. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St Paul, MN, 1991. (4) T. H. Williams and P. S. W. Liu. Phytopathol. Pap. 19:1, 1976.

Matched MeSH terms: Soil
Fulltext Encapsulating peritoneal sclerosis associated with Burkholderia pseudomallei peritonitis

Aulia Z, Wan Ali WASR, Shahar MA

Saudi J Kidney Dis Transpl, 2018 12 28;29(6):1484-1487.
PMID: 30588983 DOI: 10.4103/1319-2442.248318

Burkholderia pseudomallei is a known motile organism in soil. Its infection is usually described in immunocompromised patients. It inflicts serious infection with high mortality and morbidity rate. We report a rare case of an end-stage renal disease patient on regular continuous ambulatory peritoneal dialysis (PD) who developed melioidosis PD peritonitis. Within a short period of time, she developed encapsulating peritoneal sclerosis evidenced by the intraoperative findings of intraabdominal cocooning. Choice and duration of antibiotic are important for proper eradication of the organism. Early diagnosis and treatment of both conditions also may improve the prognoses.

Matched MeSH terms: Soil
Fulltext The relationship between bacterial sources and genotype to the antimicrobial resistance pattern of Burkholderia pseudomallei

Sadiq MA, Hassan L, Aziz SA, Zakaria Z, Musa HI, Amin MM

Vet World, 2018 Nov;11(10):1404-1408.
PMID: 30532493 DOI: 10.14202/vetworld.2018.1404-1408

Background: Melioidosis is a fatal emerging infectious disease of both man and animal caused by bacteria Burkholderia pseudomallei. Variations were suggested to have existed among the different B. pseudomallei clinical strains/genotypes which may implicate bacterial susceptibility and resistance toward antibiotics.
Aim: This study was designed to determine whether the phenotypic antibiotic resistance pattern of B. pseudomallei is associated with the source of isolates and the genotype.
Materials and Methods: A collection of 111 B. pseudomallei isolates from veterinary cases of melioidosis and the environments (soil and water) were obtained from stock cultures of previous studies and were phylogenetically characterized by multilocus sequence typing (ST). The susceptibility to five antibiotics, namely meropenem (MEM), imipenem, ceftazidime (CAZ), cotrimoxazole (SXT), and co-amoxiclav (AMC), recommended in both acute and eradication phases of melioidosis treatment were tested using minimum inhibitory concentration antibiotics susceptibility test.
Results: Majority of isolates were susceptible to all antibiotics tested while few resistant strains to MEM, SXT, CAZ, and AMC were observed. Statistically significant association was found between resistance to MEM and the veterinary clinical isolates (p<0.05). The likelihood of resistance to MEM was significantly higher among the novel ST 1130 isolates found in veterinary cases as compared to others.
Conclusion: The resistance to MEM and SXT appeared to be higher among veterinary isolates, and the novel ST 1130 was more likely to be resistant to MEM as compared to others.

Matched MeSH terms: Soil
Fulltext Different Concentrations of Doxycycline in Swine Manure Affect the Microbiome and Degradation of Doxycycline Residue in Soil

Yan Q, Li X, Ma B, Zou Y, Wang Y, Liao X, et al.

Front Microbiol, 2018;9:3129.
PMID: 30619199 DOI: 10.3389/fmicb.2018.03129

Antibiotic residues that enter the soil through swine manure could disturb the number, community structure and functions of microbiota which could also degrade antibiotics in soil. Five different concentrations of doxycycline (DOX) incorporated into swine manure were added to soil to explore the effects of DOX on microbiota in soil and degradation itself. The results showed that the soil microbiome evolved an adaptation to the soil containing DOX by generating resistance genes. Moreover, some of the organisms within the soil microbiome played crucial roles in the degradation of DOX. The average degradation half-life of DOX in non-sterile groups was 13.85 ± 0.45 days, which was significantly shorter than the 29.26 ± 0.98 days in the group with sterilized soil (P < 0.01), indicating that the soil microbiome promoted DOX degradation. DOX addition affected the number of tetracycline resistance genes, depending on the type of gene and the DOX concentration. Among these genes, tetA, tetM, tetW, and tetX had significantly higher copy numbers when the concentration of DOX was higher. In contrast, a lower concentration of DOX had an inhibitory effect on tetG. At the same time, the microbial compositions were affected by the initial concentration of DOX and the different experimental periods. The soil chemical indicators also affected the microbial diversity changes, mainly because some microorganisms could survive in adversity and become dominant bacterial groups, such as the genera Vagococcus and Enterococcus (which were associated with electrical conductivity) and Caldicoprobacter spp. (which were positively correlated with pH). Our study mainly revealed soil microbiota and DOX degradation answered differently under variable concentrations of DOX mixed with swine manure in soil.

Matched MeSH terms: Soil
Microbial Community Structure in a Malaysian Tropical Peat Swamp Forest: The Influence of Tree Species and Depth

Too CC, Keller A, Sickel W, Lee SM, Yule CM

Front Microbiol, 2018;9:2859.
PMID: 30564202 DOI: 10.3389/fmicb.2018.02859

Tropical peat swamp forests sequester globally significant stores of carbon in deep layers of waterlogged, anoxic, acidic and nutrient-depleted peat. The roles of microbes in supporting these forests through the formation of peat, carbon sequestration and nutrient cycling are virtually unknown. This study investigated physicochemical peat properties and microbial diversity between three dominant tree species: Shorea uliginosa (Dipterocarpaceae), Koompassia malaccensis (legumes associated with nitrogen-fixing bacteria), Eleiodoxa conferta (palm) and depths (surface, 45 and 90 cm) using microbial 16S rRNA gene amplicon sequencing. Water pH, oxygen, nitrogen, phosphorus, total phenolic contents and C/N ratio differed significantly between depths, but not tree species. Depth also strongly influenced microbial diversity and composition, while both depth and tree species exhibited significant impact on the archaeal communities. Microbial diversity was highest at the surface, where fresh leaf litter accumulates, and nutrient supply is guaranteed. Nitrogen was the core parameter correlating to microbial communities, but the interactive effects from various environmental variables displayed significant correlation to relative abundance of major microbial groups. Proteobacteria was the dominant phylum and the most abundant genus, Rhodoplanes, might be involved in nitrogen fixation. The most abundant methanogens and methanotrophs affiliated, respectively, to families Methanomassiliicoccaceae and Methylocystaceae. Our results demonstrated diverse microbial communities and provide valuable insights on microbial ecology in these extreme ecosystems.

Matched MeSH terms: Soil
Fulltext Aquaponics recirculation system: a sustainable food source for the future water conserves and resources

Azizah Endut, Fathurrahman Lananan, Ahmad Jusoh, Wan Norsani Wan Nik, Nora'aini Ali

Malaysian Journal of Applied Sciences, 2018;1(1):1-12.
MyJurnal

The current and escalating extent of soil degradation, water scarcity and environmental concern
plaguing agricultural productivity, demands re-assessing the direction of food production. Aquaponics
is a concept relatively new to modern food production methods and can contribute to food security.
This study was conducted to establish sustainable aquaculture systems that maximize benefits and
minimize the accumulation of detrimental compounds and other types of negative impacts on both
natural and social environments. This study carried out at an average inflow rate of 1.28 m/day to
evaluate the operation of the aquaponics recirculation system (ARS) on nutrients removal and growth
and yield of African catfish as well as water spinach. A special design of ARS was used to provide
nitrification of fishery wastewater, where the combination of sands and gravels in hydroponics trough,
providing both surfaces for biofuel development and cultivation area for plants. Removal efficiencies
of 5-day biochemical oxygen demand (BOD5), total suspended solids (TSS), total ammonia nitrogen
(TAN), nitrite-nitrogen (NO2-N), nitrate-nitrogen (NO3-N), and orthophosphate (PO4
3-
) were 82%, 89%,
93%, 94%, 81%, and 80%, respectively. The feed conversion ratio (FCR) and specific growth rate
(SGR) of African catfish were 1.08 and 3.34% day-1
, respectively. The average water spinach
production was 3.56 kg per m2
. This study showed that ARS is a method of producing crop along with
a healthy protein source and among the best alternatives for achieving economic and environmental
sustainability.

Matched MeSH terms: Soil
Insect succession associated with a hanging pig carcass placed in an oil palm plantation in Malaysia

Heo CC, Sallehudin Sulaiman, Hidayatulfathi Othman, Baharudin Omar, Jeffery J, Kurahashi H

Sains Malaysiana, 2010;39.

This study was carried out in an oil palm plantation in Tanjung Sepat, Selangor in September 2007 by using pigs (Sus scrofa L.) as a carcass model in a forensic entomological research. A 2.5 month old pig (10 kg) which died naturally was hanged on a palm tree to observe the insect succession and decomposition stages. Observation was made for 16 days; one afternoon visit per day and all climatological data were recorded. On the first day, adult muscids of Ophyra spinigera Stein and Musca domestica L. were observed, however no blowfly (Calliphoridae) activities were sighted. Fly eggs wer seen on the second day on both sides of the face, inside nostrils and genitourinary area. Adults of Chrysomya megacephala Fabricius and Chrysomya rufifacies (Macquart) congregated on the head and anal areas. Adult flies and maggots (first and second instars) were observed in the mouth and anus of the pig on the third day of hanging. Adult yellow jackets (Vespidae) and spiders (Arachnida) were found preying on some adult flies. Rove beetles (Staphilinidae) were also discovered on the pig carcass. Only a few ants (Formicidae) were sighted. Maggot masses were found in eye orbits, neck, and genital organs on the fourth day of hanging and some maggots were seen falling down to the ground. The dominant maggot species identified on this day was Ch. megacephala. On the sixth day, the head, neck, and anus were in the stage of active decay. Maggots of Ch. rufifacies were abundant on the seventh day and was the dominant species. On day eight the carcass fell onto the ground. Chrysomya rufifacies maggots were found underneath the pig carcass and they started to migrate and pupated under the soil. On the tenth day, third instar Op. spinigera maggots were found under the carcass. The rate of carcass decomposition slowed down and became stable from tenth day onwards to the sixteenth day of decomposition. Thereafter, most of the remaining parts of the body remained dried and devoid of any insects.

Matched MeSH terms: Soil
A review of bioretention components and nutrient removal under different climates-future directions for tropics

Goh HW, Lem KS, Azizan NA, Chang CK, Talei A, Leow CS, et al.

Environ Sci Pollut Res Int, 2019 May;26(15):14904-14919.
PMID: 30977005 DOI: 10.1007/s11356-019-05041-0

Bioretention systems have been implemented as stormwater best management practices (BMPs) worldwide to treat non-point sources pollution. Due to insufficient research, the design guidelines for bioretention systems in tropical countries are modeled after those of temperate countries. However, climatic factors and stormwater runoff characteristics are the two key factors affecting the capacity of bioretention system. This paper reviews and compares the stormwater runoff characteristics, bioretention components, pollutant removal requirements, and applications of bioretention systems in temperate and tropical countries. Suggestions are given for bioretention components in the tropics, including elimination of mulch layer and submerged zone. More research is required to identify suitable additives for filter media, study tropical shrubs application while avoiding using grass and sedges, explore function of soil faunas, and adopt final discharged pollutants concentration (mg/L) on top of percentage removal (%) in bioretention design guidelines.

Matched MeSH terms: Soil
Comparative effects of different soil conditioners on wheat growth and yield grown in saline-sodic soils

Zia-ur-Rehman M, Sabir M, Shahjahan, Ahmed HR, Muhammad Rizwan, Ali S

Sains Malaysiana, 2016;45:339-346.

Among abiotic stresses, salinity is the main abiotic stress limiting crop growth and yield worldwide. Improving agri-food production in salt-prone areas is the key to meet the increasing food demands in near future. A greenhouse experiment was conducted to investigate the effect of different soil conditioners, gypsum (GYP), citric acid (CA), ethylene diamine tetraacetic acid (EDTA) and polyvinyl alcohol (PVA), on growth and yield of wheat (Triticum aestivum L.) grown in salinesodic soil. Gypsum was applied at a rate of 100% soil gypsum requirement while other amendments were applied each at a rate of 5 g kg-1 of soil. The results showed that EDTA treatment increased pH and electrical conductivity (ECe) of soil while pH significantly decreased when treated with citric acid. Soil sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) decreased in all treatments following the order: CT > PVA > EDTA > CA > GYP. Addition of CA positively affected growth parameters as compared to other soil conditioners including plant height, number of tillers per plant, number of spikes per plant, plant dry weight and grain yield while EDTA negatively affected these parameters. Addition of CA also significantly increased photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll contents while EDTA decreased these parameters. We conclude that increase in plant growth and yield with CA might be due to the effect of CA on soil properties which positively affected plant physiological parameters.

Matched MeSH terms: Soil
Initial screening of mangrove endophytic fungi for antimicrobial compounds and heavy metal biosorption potential

Ling Onn M, Teen Lim P, Aazani Mujahid, Proksch P, Müller M

Sains Malaysiana, 2016;45:1063-1071.

Endophytic fungi provide protection to their host plant and the fungi often produce antimicrobial compounds to aid the host
fighting off pathogens. These bioactive compounds were secondary metabolites which were often produced as waste- or
by-products. In the present study, endophytic fungi isolated from mangrove plants and soils were characterized and their
antimicrobial production and bioremediation potential of heavy metals copper (Cu) and zinc (Zn) were assessed. Twelve
(12) isolated and identified endophytic fungi belonged to seven species; Penicillium, Curvularia, Diaporthe, Aspergillus,
Guignardia, Neusartorya and Eupenicillium. Antimicrobial activities of these 12 fungal endophytes were tested against
Gram negative bacteria; Bacillus subtilis, Staphylococcus aureus, Gram positive bacteria; Escherichia coli and fungi;
Candida albicans and Aspergillus niger among others. Two isolates (related to Guignardia sp. and Neusartoya sp.) showed
strong antimicrobial (and antifungal) activity whereas the rest showed no activity. Compounds were isolated from both
isolates and screened using HPLC. Both isolates displayed chemically very interesting chromatograms as they possessed a
high diversity of basic chemical structures and peaks over a wide range of polarities, with structures similar to Trimeric
catechin and Helenalin among others. For bioremediation assessment, the results showed maximum biosorption capacity
for two isolates related to Curvularia sp. and Neusartorya sp., with the former removing 25 mg Cu/g biomass and the
latter removing 24 mg Zn/g biomass. Our results indicated the potential of mangrove endophytic fungi in producing
bioactive compounds and also highlighted their potential for the treatment of heavy metal-contaminated wastewater.

Matched MeSH terms: Soil
Bacterial diversity and community structure of banana rhizosphere in orang asli fields and commercial plantations

Lee JYN, Tan IKP

Sains Malaysiana, 2018;47:243-251.

Bacteria play an important roles in the soil ecosystem and in the rhizosphere, they are intricately linked to nutrient content
and its accessibility to plants, plant protection and sometimes pathogenicity. Banana grows well in the tropics and it is
popularly grown in Orang Asli (OA) (indigenous people) settlements. Banana is also grown in commercial plantations.
In traditional planting practices, the OA do not add pesticide nor fertilizer to their crops which are planted for selfsustenance
mainly. On the other hand, fertilizer and pesticide are added to commercial banana plantations to maximise
yield. Rhizosphere bacteria from the banana plant, Pisang Nipah, grown in OA fields and commercial plantations were
identified by clone library construction of the 16S rRNA gene. This was to determine whether farming practices influenced
the bacterial community in the banana plant rhizosphere. Acidobacteria, Proteobacteria and Actinobacteria were found in
all the soil. Other common phyla found in some soil (but not all) were Nitrospirae, Firmicutes, Bacteroidetes, Chloroflexi,
Verrumicrobia, Gemmatimonadetes and Cyanobacteria. The bacterial diversity was a little more diverse in the OA fields
than the commercial plantations. The latter had higher contents of nitrogen, phosphorus and potassium. These could
have exerted selective pressure to reduce the bacterial diversity in the commercial plantations.

Matched MeSH terms: Soil
Fulltext Correlation between Soil Transmitted Helminth Infection and Eosinophil Levels among Primary School Children in Medan

Darlan DM, Tala ZZ, Amanta C, Warli SM, Arrasyid NK

Open Access Maced J Med Sci, 2017 Apr 15;5(2):142-146.
PMID: 28507618 DOI: 10.3889/oamjms.2017.014

BACKGROUND: Soil Transmitted Helminth infection is one of most prevalent health problems worldwide, especially in environments with poor sanitation. Based on World Health Organisation (WHO) data, more than 2 billion people, or 24% of the world's population, are infected with intestinal parasite. The highest prevalence is located in areas of poor sanitation and unsafe water supplies. In Indonesia, the prevalence of parasite infections is 15% of the entire population.
AIM: The purpose of this study was to determine the relationship between Soil Transmitted Helminth infection on levels of eosinophils among primary school children. In addition, this study also aimed to determine the prevalence of different types of worm infections and the levels of eosinophils in children infected with worms.
MATERIAL AND METHODS: This study was analytic observational using a cross-sectional method. The sampling technique was consecutive and in total 132 samples was obtained. The study involved primary school children in Amplas Medan and Hamparan Perak, Deli Serdang through May to October 2016. Univariate analysis was performed to determine STH infection prevalence and bivariate analysis was used to find the correlation between STH infection and eosinophil levels through a Chi square (χ2) test.
RESULTS: The results showed that the prevalence of Soil Transmitted Helminth was 7.6%. The most common types of STH infection were 3.8% with Trichuris trichiura and 3% with Ascaris lumbricoides. A significant correlation was found between Parasite infection and eosinophil levels (Contingency Coefficient (C) = 0.2, χ2 = 5.3, p = 0.021) and the risk of STH infection that caused eosinophilia or increased eosinophil levels in the children with a Prevalence Ratio (PR) of 1.56 (Confidence Interval (CI) 95%: 1.10-2.22).
CONCLUSION: It is recommended that schools at similar risk improve and maintain hygiene and healthy behaviour in the school environment and that parents and teachers pay greater attention to the cleanliness of their children.

Matched MeSH terms: Soil
Rhizosphere Metagenomics of Paspalum scrobiculatum L. (Kodo Millet) Reveals Rhizobiome Multifunctionalities

Prabha R, Singh DP, Gupta S, Gupta VK, El-Enshasy HA, Verma MK

Microorganisms, 2019 Nov 23;7(12).
PMID: 31771141 DOI: 10.3390/microorganisms7120608

Multifunctionalities linked with the microbial communities associated with the millet crop rhizosphere has remained unexplored. In this study, we are analyzing microbial communities inhabiting rhizosphere of kodo millet and their associated functions and its impact over plant growth and survival. Metagenomics of Paspalum scrobiculatum L.(kodo millet) rhizopshere revealed taxonomic communities with functional capabilities linked to support growth and development of the plants under nutrient-deprived, semi-arid and dry biotic conditions. Among 65 taxonomically diverse phyla identified in the rhizobiome, Actinobacteria were the most abundant followed by the Proteobacteria. Functions identified for different genes/proteins led to revelations that multifunctional rhizobiome performs several metabolic functions including carbon fixation, nitrogen, phosphorus, sulfur, iron and aromatic compound metabolism, stress response, secondary metabolite synthesis and virulence, disease, and defense. Abundance of genes linked with N, P, S, Fe and aromatic compound metabolism and phytohormone synthesis-along with other prominent functions-clearly justifies growth, development, and survival of the plants under nutrient deprived dry environment conditions. The dominance of actinobacteria, the known antibiotic producing communities shows that the kodo rhizobiome possesses metabolic capabilities to defend themselves against biotic stresses. The study opens avenues to revisit multi-functionalities of the crop rhizosphere for establishing link between taxonomic abundance and targeted functions that help plant growth and development in stressed and nutrient deprived soil conditions. It further helps in understanding the role of rhizosphere microbiome in adaptation and survival of plants in harsh abiotic conditions.

Matched MeSH terms: Soil

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