In this study, a Lactic acid bacteria (LAB) strain was isolated on MRS medium from gastro-intestinal tissues of Broadhead catfish (Clarias macrocephalus). Out of 50 isolates, 25 isolates were found to be positive on lactose utilisation test and were identified to be gram positive cocci. Using disc diffusion methods, one out of 22 isolates, i.e., a strain A5 demonstrated inhibitions against three indicator organisms; Bacillus cereus, Staphylococcus aureus and Salmonella thyphimurium. Partial 16S rDNA sequencing identified isolate A5 as a member of Lactococcus lactis, with 100% DNA homology. Cell free supernatant fluid from Lactococcus lactis A5 showed inhibitory activities against both gram positive pathogens (Bacillus cereus and Staphylococcus aureus) and gram negative pathogens (Salmonella thyphimurium). Chloroform precipitated bacteriocin retained antagonistic activities in the presence of catalase and lysozyme; and was completely inactivated by Proteinase K treatment. The bacteriocin has a molecular weight of 3.4 kDa, based on SDS-PAGE analysis and the extract was heat stable at 37°C and 65°C, for 15 minutes. The antibacterial activity was suppressed with the addition of EDTA but was significantly increased with the addition of SDS, Triton X-100, Tween 20 and Tween 80. This bacteriocin belongs to class 1 bacteriocin, which was shown to have a nisin-like properties. This strain can be used as potential probiotics in animal or aquaculture feeding; and the bacteriocin it produces will be useful in food preservative.
Leaf litter decomposition in a tropical stream was examined in two types of leaf packs; single species leaf packs of Pometia pinnata and two species leaf packs of equal combination of Pometia pinnata and Dolichandrone spathacea leaves. Both leaf packs were immersed in a river and weekly examined for remains of decomposed leaves and presence of EPT. In the control leaf packs, leaves in the two species leaf packs treatments decomposed within 35 days, faster than in single species leaf packs which decomposed after 42 days. In the presence of EPT, the leaf breakdown took 28 days in two species and 35 days for single species leaf packs. Higher abundance of EPT was observed in single species leaf packs but its diversity was higher in two species leaf packs. Litter breakdown in the stream was faster in the presence of EPT and softer leaves of D. spathacea with higher nitrogen content underwent faster decomposition and sustained higher numbers of EPT.
Stable isotope analysis has been used extensively to establish trophic relationships in many ecosystems. Present study utilised stable isotope signatures of carbon and nitrogen to identify trophic structure of aquatic food web in river and rice field ecosystems in Perak, northern peninsular Malaysia. The mean δ(13)C values of all producers ranged from -35.29 ± 0.21 to -26.00 ± 0.050‰. The greatest δ(15)N values noted was in zenarchopterid fish with 9.68 ± 0.020‰. The δ(15)N values of aquatic insects ranged between 2.59 ± 0.107 in Elmidae (Coleoptera) and 8.11 ± 0.022‰ in Nepidae (Hemiptera). Correspondingly, with all the δ(13)C and δ(15)N values recorded, it can be deduced that there are four trophic levels existed in the freshwater ecosystems which started with the producer (plants), followed by primary consumer (aquatic insects and non-predatory fish), secondary consumer (invertebrate predators) and lastly tertiary consumer (vertebrate predators).
Recent studies suggested that combined treatment approaches can be used to improve anticancer potency and circumvent the limitations of high-dose tocotrienols administration. Acalypha wilkesiana is a medicinal plant that has been used as an adjunct treatment for cancers in traditional medicine. Herein, the effects of single and combined treatments of β-, γ- and δ-tocotrienols and ethyl acetate extract (9EA) of Acalypha wilkesiana on lung (A549) and brain (U87MG) cancer cells were investigated. γ- and δ-tocotrienols exhibited higher potent antiproliferative effects against A549 (12.1 μg/ml and 13.6 μg/ml) and U87MG cells (3.3 μg/ml and 5.2 μg/ml) compared to β-tocotrienols (9.4 μg/ml and 92.4 μg/ml), respectively. Whereas, 9EA induced potent antiproliferative effects against U87MG cells only (2.0 μg/ml). Combined treatments of tocotrienols and 9EA induced a synergistic growth inhibition with up to 8.4-fold reduction in potent doses of β-, γ- and δ-tocotrienols on A549 cells. Apoptotic features were also evidenced on A549 cells receiving single and combined treatments. The synergism may greatly improve the therapeutic outcome for lung cancer.
The occurrence of major outbreaks of dengue, and other vector borne diseases such as chikungunya and zika in tropical and subtropical regions has rendered control of the diseases a top-priority for many affected countries including Malaysia. Control of the mosquito vectors Aedes aegypti and Aedes albopictus through the reduction of breeding sites and the application of insecticides to kill immature forms and adults are the main control efforts to combat these diseases. The present study describes the association between Ae. albopictus and Ae. aegypti in shared breeding sites. This study is important given that any measure taken against one species may affect the other. A yearlong larval survey was conducted in four dengue endemic areas of Penang Island. Sorenson's coefficient index indicated that no association between number of the immatures of the two species regardless of container size and study location. Therefore, the mean number Ae. albopictus immature was not decreased in the presence of Ae. aegypti in shared breeding container. However Ae. aegypti appeared to prefer breeding in habitats not occupied by Ae. albopictus, the two species sharing breeding sites only where available containers were limited. In control efforts, eliminating the preferred breeding containers for one species might not affect or reduce the population of the other species.
This study was conducted to determine the physical and chemical composition of goat milk produced by eight local farms located in the central region of Malaysia. Farms 1 to 4 (F1-SC, F2-SP, F3-SP, F4-SBC) reared Saanen-type goats while farms 5 to 8 (F5-JK, F6-JPEC, F7-JTC, F8-JC), Jamnapari-type goats. The common feedstuffs used in all farms comprised of fresh or silage from Napier grass, feed pellets, and brans while two farms, F5-JK and F6-JPEC supplemented the feeds with soybean-based product. The total solid content, dry matter, and proximate composition of goat milk and feedstuffs from the different farms were determined and the results analysed using principal component analysis. Total solid content of goat milk from the Jamnapari crossbreed had the highest solid content ranging from 11.81% to 17.54% compared to milk from farms with Saanen and Saanen crossbreed (10.95% to 14.63%). Jamnapari-type goats from F5-JK, F6-JPEC, and F8-JC had significantly higher (p < 0.05) milk fat and protein contents (7.36%, 7.14%, and 6.59% fat; 5.08%, 6.19%, and 4.23% protein, respectively) than milk from other farms but, milk produced by Saanen-type goats from F4-SBC contained similar protein content (4.34%) to that from F8-JC. Total ash and carbohydrate contents in milk ranged between 0.67% to 0.86% and 3.26% to 4.71%, respectively, regardless of goat breed. Feeding soybean-based products appear to have a positive influence on milk fat and protein content in Jamnaparitype goats.
The objective of this study was to investigate the influence of spent mushroom compost of Pleurotus eous strain P-31 on the growth and yield performance of pepper and tomato seedlings under greenhouse conditions. Sandy loam soil was combined with different percentages of SMC to obtain the following combinations (0, 5, 10, 15, 20, 25 and 30) %. Lower concentrations SMC5, SMC10 and SMC15 promoted vegetative growth (plant height, leaf area, chlorophyll content, number of leaves and axillary branches) of the two test plants. Tomato seedlings grown in SMC10 recorded the highest plant height (50.3 ± 7.2cm); leaf area (378.8 ± 1.2cm2); number of floral buds (51) and flowers (28) whereas SMC5 recorded the highest chlorophyll content 34.1 ± 0.9CCI though SMC15 recorded the highest number of leaves (8). Tomato seedlings grown in SMC30 produced both the maximum number of fruits (8) with corresponding high weight (34.2 ± 7.7g). Pepper seedlings grown in lower concentrations (SMC5-15) recorded the highest plant heights (29.8-30.8cm), chlorophyll content (20.3CCI) and leaf area (53.5-66.2 cm2). Although the different combinations of sandy loam soil and SMC did not significantly (p ≥ 0.05) affect the number of axillary branches developed; different combinations significantly (p ≤ 0.05) affected the number of floral bud, flower and fruit, weight of fruits formed and value of each of these increased with increasing percentage of SMC. Pepper seedlings grown on SMC30 recorded the maximum number of floral buds (32.0 ± 3.6), number of flowers (19.4 ± 1.3), number of fruits (10.8 ± 1.2) and weight of fruits (31.9 ± 3.4g). Tomato seedlings raised on SMC100 (spent mushroom compost only) and soil only did not significantly (p ≥ 0.05) differ from each other however, was statistically significant (p ≤ 0.05) from amended sandy loam soil by all criteria investigated. The study shows that SMC provide favourable soil conditioners for the cultivation of fruits, vegetables and foliage crops as it improved growth and yield of tomato and pepper seedlings.
Data on nutrient contents of freshwater crabs are important for ecological studies and species conservation assessments, especially when the species concerned is threatened among others by habitat destruction and uncontrolled resources utilisation. Indeed comprehensive biological information is required to reconcile the needs between sustainable resources utilisation and conservation of the species. This study documents the nutrient contents of a freshwater crab, Isolapotamon bauense which is listed as 'Vulnerable' in the IUCN Red List of Threatened Species and also being harvested by local community for dietary supplement. Results show that muscles of the freshwater crab contain a substantial amount of nutrients in particular water content (male = 79.31 ± 2.30 %, female = 77.63 ± 0.56 %), protein (male = 77.47 ± 6.11 %, female = 63.28 ± 3.62 %), magnesium (male = 51.48 ± 16.10 mg/g, female = 39.73 ± 6.99 mg/g) and calcium (male = 25.50 ± 6.98 mg/g, female = 39.73 ± 6.99 mg/g). Means of nutrient contents between male and female crabs are not significantly different. It is estimated that an individual of I. bauense with weight range of 56-139 g contained on average of 0.35 ± 0.15 g of protein. Our estimation also shows that the number of individuals of the freshwater crab required to meet the recommended daily protein intakes of the community concerned is in the range 35-96 individuals for children, 130-188 individuals for adolescents, 171-179 individuals for men and 149-159 individuals for women. The results imply that harvesting of wild I. bauense as a source of protein supplement naturally may not be practical because of its relatively low population abundance, and conservation of the species for its ecological roles may thus be preferred.
Burkholderia pseudomallei is a soil-dwelling bacterium that causes a globally emerging disease called melioidosis. Approximately one third of the in silico annotated genes in its genome are classified as hypothetical genes. This group of genes is difficult to be functionally characterised partly due to the absence of noticeable phenotypes under conventional laboratory settings. A bioinformatic survey of hypothetical genes revealed a gene designated as BPSL3393 that putatively encodes a small protein of 11 kDA with a CoA binding domain. BPSL3393 is conserved in all the B. pseudomallei genomes as well as various in other species within the genus Burkholderia. Taking into consideration that CoA plays a ubiquitous metabolic role in all life forms, characterisation of BPSL3393 may uncover a previously over-looked metabolic feature of B. pseudomallei. The gene was deleted from the genome using a double homologous recombination approach yielding a null mutant. The BPSL3393 mutant showed no difference in growth rate with the wild type under rich and minimal growth conditions. An extensive metabolic phenotyping test was performed involving 95 metabolic substrates. The deletion mutant of BPSL3393 was severely impaired in its ethanolamine metabolism. The growth rate of the mutant was attenuated when ethanolamine was used as the sole carbon source. A transcriptional analysis of the ethanolamine metabolism genes showed that they were down-regulated in the BPSL3393 mutant. This seemed to suggest that BPSL3393 functions as a positive regulator for ethanolamine metabolism.
In this study, bifenthrin (Maxxthor SC, Ensystex Australasia Pty Ltd), imidacloprid (Prothor SC, Ensystex Australasia Pty Ltd) and fipronil (Regent(®)50SC, Bayer) were applied on the natural infest manures according to the manufacturer rate during a broiler breeding cycle. Solvent direct-immersion extraction (SDIE) was used in detecting the target compound and later, quantification of the insecticide residues in field condition was investigated. The samples were prior cleaned up by solid-phase extraction (SPE) and analysed by Ultra-Performance Liquid Chromatography (UPLC) - photodiode array (PDA) system. In the field trial, three insecticides were showed accumulation during the broiler breeding period and it is suggested that they acted as adulticides when applied on the poultry manures, this is supported by the significant correlation between the increment of insecticide residues to the reduction percentage of adult flies (<0.05). Fipronil showed significantly greater reduction on the adult fly compared to the other insecticides, in which the reduction rate compared to control population at the end of the broiler breeding period; fipronil, imidaclopril and bifenthrin reduced 51.51%, 28.30% and 30.84% of adult flies, respectively.
The population of bats has declined from year to year caused by human activities such as logging and hunting activities. Since the human factor is linked to the issues of population decline in many animal species, a community-based conservation strategy that involved local communities is needed. We conducted face-to-face surveys among residents in Penang Island to assess knowledge and awareness level toward bats conservation efforts. We collected demographic values such as age, gender, level of education, length of residency as well as their monthly income, since different group in these variable might have different perception. We found that age groups, level of education and monthly income have shown significant differences among the respondents. However, no other significant differences were indicated for by gender and length of residency. Respondent's knowledge of bats showed that the majority of the respondents were less likely to value the importance of bats in the ecosystem. We recommended stronger legal system, earlier exposure towards environmental education, well-planned urbanisation implementation and long-term monitoring programs to strengthen efforts in conserving bats in Malaysia.
A small scale laboratory study was conducted to determine the effects of
salinity ranging from 15, 20, 25, 30, 35, 40, and 45 ppt on the filtration rates of juvenile
oyster Crassostrea iredalei with 25 ppt as the control. Three juvenile oysters (shell weight:
1.04 ± 0.12 g; shell length: 1.9 ± 0.2 cm; shell height: 1.9 ± 0.1 cm) were used to test the
filtration rates in each salinity over the course of 8 hours. The hourly filtration rates were
determined from the exponential decrease in algal (Chaetoceros calcitrans) concentration
as a function of time. The oyster in 35 ppt salinity produced the highest overall filtration
rate (FR2) with 134.06 ± 15.66 mL–1 hr–1 oyster–1 and the lowest overall filtration rate (FR2)
occurred in oyster exposed to 15 ppt and 45 ppt with 31.30 ± 6.90 mL–1 hr–1 oyster–1 and
32.11 ± 7.68 mL–1 hr–1 oyster–1
respectively throughout the 8 hours. The result from this
study can be useful for optimum oyster culturing and the oysters can be employed as a
natural biofilter in marine polyculture farming.
Like many other countries, reservoirs in Malaysia are primarily built for various
functions such as hydroelectric power generation, drinking water supply, flood mitigation
and irrigation for agricultural purposes. Artisanal fisheries activities were also performed in
these reservoirs. The freshwater fish are a requisite source of protein for the rural
population. Consequently, the fish resources in reservoirs should be carefully maintained
at sustainable level. Present study elucidates the preliminary assessment on autecological
studies of beardless barb, Cyclocheilichthys apogon as a model of fish biota in Muda
Reservoir. This research investigates the growth pattern of C. apogon using length-weight
relationship and their condition factor. A total of 307 specimens were captured using cast
net for six consecutive months from March 2014 until August 2014. The growth coefficient
(b) from the length-weight equation (W = aLb
) for male and female of C. apogon were
3.150 and 3.185, respectively, indicating positive allometric growth. The condition factor
values of male and female of C. apogon were 1.023 ± 0.111 and 1.026 ± 0.100,
respectively, suggesting that C. apogon is in good condition in Muda Reservoir. The
paucity of research on the autecological study in the Muda Reservoir contributes to the
main reason of performing this research. The findings will serve as baseline information of
this species in Muda Reservoir, as well as for comparative study in the future.
Benthic faunal communities are important components in the intertidal zones.
The diversity and abundance of the benthic communities are subjected to different natural
and anthropogenic disturbances. The study was conducted as one off sampling on 6th
November 2013 (1) to investigate the abundance and distribution of soft sediment
communities in relation to environmental variables and (2) investigate the changes of
population structure and diversity using spatial scales of 1 m, 10 m, and 100 m. Results
indicated a total of 110 individuals of macrobenthos consisting of 7 different groups
(Annelida, Bivalvia, Crustacea, Gastropoda, Nematoda, Nemertea, Polychaeta) and 4
different groups of meiobenthos (Copepoda, Nematoda, Ostracoda, Polychaeta)
consisting 920 individuals were recorded. Dissolved oxygen played the most significant
role in affecting the distribution of soft sediment communities while ammonia
concentrations only affected marcobenthic organisms. However, sediment grain size did
not show significant correlation (p>0.05) on soft sediment communities. Hence,
understanding how different properties of benthos respond to changes in environmental
variables is crucial in determining how the impacts on the sediment are tolerated by the
benthic organisms.
A study was conducted at five selected rivers around Bukit Merah Reservoir,
Perak, Malaysia for eight weeks in order to determine the fish diversity and distribution. A
total of 28 species comprised of 9 families were identified. The study depicted that there
were significant changes to the fish composition when compared to previous study which
had captured 36 species due to different areas covered and different types of sampling
gear used between both studies.
Coral reefs in the northern region of the Straits of Malacca have a diverse group
of octocorals growing on its bed. The octocorals identified in this study are from islands
along the Straits. In this study, 23 specimens were identified, belonging to 4 sub-orders,
which have been subdivided into 8 families. From these 8 families, 15 different genera
have been identified. The identification process for this research was conducted based on
five important keys; the external form and colouration, polyps or colonial and fundamental
structure of colonies, monomorphic or dimorphic, the arrangement of polyps, and the
arrangement of sclerites.
Paederus fuscipes Curtis is a nocturnal insect. The attractiveness of artificial
light sources from residential premises eventually causes the risk of severe dermatitis
effect, once Paederus is in contact with human skin. The objective of this study is to
investigate whether the light and height factors of residential buildings and its’ association
to rice cultivation phases are primary reasons for P. fuscipes’s mass dispersal into human
residential areas. The study site was located in residential premises that were built
adjacent to rice field areas (≈ 32–60 m and 164 m) north of the rice field located in Teluk
Air Tawar, mainland of Pulau Pinang. Overall, both light sources and rice cultivation
phases caused a significant effect for P. fuscipes beetles dispersal flight to invade human
settlements. More P. fuscipes were captured near the bright light source with the highest
number of beetles found during harvesting stage. Whereas, significantly higher number of
P. fuscipes were captured at level 2 and 3 compared to ground and level 1 of the
apartment building and P. fuscipes was also found significantly affected by the rice
cultivation phases at different elevation levels. This indicates that bright light sources and
higher elevation levels are the main factors in attracting P. fuscipes beetles to disperse
and causes infestations in residential areas. This finding could create awareness among
the public on P. fuscipes dispersal pattern.
The influence of the cool and warm temperatures on early life development and
survival of tropical oyster, Crassostrea iredalei was studied. D-hinged larvae (day 1 larvae)
were reared to three different temperatures (20°C, 27°C, and 34°C) for nine days. Oyster
larvae reared in temperature 27°C, acted as control (ambient temperature). The highest
survival rate occurred when the larvae were reared in 20°C and 27°C. Larvae reared at
34°C exhibited reduced survival but increase in the growth rate. The growth rate in larvae
reared in high temperature (34°C) was significantly higher compared to larvae reared in
20°C and 27°C (p
The nesting of green turtle (Chelonia mydas) was monitored from 1998 untill 2013 along the beaches of Pasir Panjang, Segari, Perak. The objective of the study is to assess the nesting status of green turtles in Perak, Peninsular Malaysia in terms of total nests, eggs, survival hatchings, and density of visitors. A total number of green turtle nests found for 16 years were 1,019 nests and varied from 10 to 220 nests per year. Meanwhile, the sum of eggs collected for 16 years were 107,820 eggs, and varied from 553 to 20,881 eggs per year. The temporal pattern of nesting indicates year-round nesting in Perak in most years within the 16 years period. The peak season of nesting was estimated to occur between May and June. Survival hatchlings varied from 23.33% (2,071 hatchlings) to 55.03% (5,018 hatchlings) from 1998 to 2013. The density of visitors was not uniformly distributed among the years, and shows a sign of decline especially from 2006 onwards. This publication provides basic knowledge of green turtle nesting population in Perak, and would be helpful in upgrading the conservation program in Malaysia. In future, we hope 1) for an increase in manpower to obtain accurate nesting records along the nesting beaches during nocturnal survey and, 2) to include the breeding biology data such as nest placement, emergence hour, and morphological characteristics of green turtle.
Tarsius bancanus borneanus was first reported by Elliot in 1990 which an endemic species that can be found on the Island of Borneo consisting of Sabah and Sarawak of Malaysia, Brunei Darussalam and Kalimantan, Indonesia. This sub-species has been listed as a totally protected animal under the Sarawak Wild Life Protection Ordinance (1998) and vulnerable by the International Union for Conservation of Nature (IUCN). The present study was conducted at Universiti Putra Malaysia Bintulu Campus (UPMKB), Sarawak from October 2014 till March 2015. Through mark and recapture sampling covering an area of 37 ha of secondary forest patches and 7.13 ha of rehabilitated forest, a total of 16 tarsiers were captured using mist nets while one tarsier was recapture. The population density was 38 individuals/km2 was captured using mist nets in the secondary forest while 28 individuals/km2 was recorded for the rehabilitated forest. Using the catch per unit effort (net hour) method, the average time for capturing tarsiers in the secondary forest patches was 26.6 net hour per animal and 30.0 net hour per animal in the rehabilitated forest. The presented results provides information on the presence of tarsiers in both the secondary and rehabilitated forests of UPMKB, Sarawak, Malaysia which underlines the conservation value of these forested areas.