The nutritive value of spontaneously fermented brown rice flour medida, a Sudanese cereal thin porridge, is low. This study was carried out to improve the nutritional quality of medida. The flour was soaked and malted at 30◦C to optimise the protein content. Flour malted for two days had the highest protein content. Skim milk was added to the malted brown rice flour medida and fermented using Bifidobacterium longum BB 536. Maximum count of B. longum BB 536 up to 9 log CFU/ ml was attained at 4.6 final fermentation pH. The resultant viscosity was similar to that of the spontaneously fermented brown rice flour medida. There was significant (P< 0.01) increase in both the energy density and the protein content, having increased 12 folds and 24 folds, respectively. The essential amino acids including lysine and methionine were highly augmented. The resultant medida have stable flowing characteristics and meet the whole protein and energy requirements for infants and children aged 1 - 10 years old.
Polycyclic aromatic hydrocarbons (PAHs) and linear alkylbenzenes (LABs) were used as anthropogenic markers of organic chemical pollution of sediments in the Selangor River, Peninsular Malaysia. This study was conducted on sediment samples from the beginning of the estuary to the upstream river during dry and rainy seasons. The concentrations of ƩPAHs and ƩLABs ranged from 203 to 964 and from 23 to 113 ng g(-1) dry weight (dw), respectively. In particular, the Selangor River was found to have higher sedimentary levels of PAHs and LABs during the wet season than in the dry season, which was primarily associated with the intensity of domestic wastewater discharge and high amounts of urban runoff washing the pollutants from the surrounding area. The concentrations of the toxic contaminants were determined according to the Sediment Quality Guidelines (SQGs). The PAH levels in the Selangor River did not exceed the SQGs, for example, the effects range low (ERL) value, indicating that they cannot exert adverse biological effects.
In this study, the surface sediments of the Malacca and Prai Rivers were analyzed to identify the distributions, and sources of Polycyclic Aromatic Hydrocarbons (PAHs). The total PAH concentrations varied from 716 to 1210 and 1102 to 7938 ng g(-1)dw in the sediments of the Malacca and Prai Rivers, respectively. The PAH concentrations can be classified as moderate and high level of pollution in the sediments of the Malacca and Prai Rivers, respectively. The comparison of PAHs with the Sediment Quality Guidelines (SQGs) indicates that the PAHs in the sediments of the Malacca and Prai Rivers may have the potential to cause adverse toxicity effects on the sampled ecosystems. The diagnostic ratios of individual PAHs indicate both petrogenic- and pyrogenic-origin PAHs with dominance of pyrogenic source in both rivers. These findings demonstrate that the environmental regulations in Malaysia have effectively reduced the input of petrogenic petroleum hydrocarbons into rivers.
Peninsular Malaysia has gone through fast development during recent decades resulting in the release of large amounts of petroleum and its products into the environment. Aliphatic hydrocarbons are one of the major components of petroleum. Surface sediment samples were collected from five rivers along the west coast of Peninsular Malaysia and analyzed for aliphatic hydrocarbons. The total concentrations of C10 to C36 n-alkanes ranged from 27,945 to 254,463ng·g(-1)dry weight (dw). Evaluation of various n-alkane indices such as carbon preference index (CPI; 0.35 to 3.10) and average chain length (ACL; 26.74 to 29.23) of C25 to C33 n-alkanes indicated a predominance of petrogenic source n-alkanes in the lower parts of the Rivers, while biogenic origin n-alkanes from vascular plants are more predominant in the upper parts, especially in less polluted areas. Petrogenic sources of n-alkanes are predominantly heavy and degraded oil versus fresh oil inputs.
This baseline assessment reports on the occurrence, distribution, and sources of emerging organic contaminants (EOCs) in tropical coastal sediments of anthropogenically impacted Klang River estuary, Malaysia. Bisphenol A was the highest concentration detected at 16.84 ng g-1 dry weight, followed by diclofenac (13.88 ng g-1 dry weight) and E1 (12.47 ng g-1 dry weight). Five compounds, namely, amoxicillin, progesterone, diazinon, bisphenol A, and E1, were found in all sampling stations assessed, and other compounds such as primidone, diclofenac, testosterone, E2, and EE2 were ubiquitously present in sediment samples, with percentage of detection range from 89.04% to 98.38%. Organic carbon content and pH were the important factors controlling the fate of targeted compounds in the tropical estuarine sediment. On the basis of the literature from other studies, the sources of EOCs are thought to be from wastewater treatment plants, domestic/medical waste discharge, livestock activities, industrial waste discharge, and agricultural activities.
A test for assessing pork adulteration in meatballs, using TaqMan probe real-time polymerase chain reaction, was developed. The assay combined porcine-specific primers and TaqMan probe for the detection of a 109 bp fragment of porcine cytochrome b gene. Specificity test with 10 ng DNA of eleven different species yielded a threshold cycle (Ct) of 15.5 ± 0.20 for the pork and negative results for the others. Analysis of beef meatballs with spiked pork showed the assay can determine 100-0.01% contaminated pork with 102% PCR efficiency, high linear regression (r(2) = 0.994) and ≤ 6% relative errors. Residuals analysis revealed a high precision in all determinations. Random analysis of commercial meatballs from pork, beef, chicken, mutton and goat, yielded a Ct between 15.89 ± 0.16 and 16.37 ± 0.22 from pork meatballs and negative results from the others, showing the suitability of the assay to determine pork in commercial meatballs with a high accuracy and precision.
A polymerase chain reaction (PCR) assay for the assessment of dog meat adulteration in meatballs was developed. The assay selectively amplified a 100-bp region of canine mitochondrial cytochrome b gene from pure, raw, processed and mixed backgrounds. The specificity of the assay was tested against 11 animals and 3 plants species, commonly available for meatball formulation. The stability of the assay was proven under extensively autoclaving conditions that breakdown target DNA. A blind test from ready to eat chicken and beef meatballs showed that the assay can repeatedly detect 0.2% canine meat tissues under complex matrices using 0.04 ng of dog DNA extracted from differentially treated meatballs. The simplicity, stability and sensitivity of the assay suggested that it could be used in halal food industry for the authentication of canine derivatives in processed foods.
Bacterial biofilms are a preferred mode of growth for many types of microorganisms in their natural environments. The ability of pathogens to integrate within a biofilm is pivotal to their survival. The possibility of biofilm formation in Lactobacillus communities is also important in various industrial and medical settings. Lactobacilli can eliminate the colonization of different pathogenic microorganisms. Alternatively, new opportunities are now arising with the rapidly expanding potential of lactic acid bacteria biofilms as bio-control agents against food-borne pathogens.
Cholera, a severe form of gastroenteritis, is one of the most widespread diseases in developing countries. The mechanism of intestinal infection caused by V. cholerae O139 remains unclear. In order to explore some morphological aspects of its infection in the intestine including Peyer's patches, we investigated the V. cholerae O139 infection at intestinal site of the rabbit gut-loop model. The electron microscopic analysis revealed denuded mucosal surface with loss of microvilli and integrity of the surface epithelium. Infection of the intestine with V. cholerae O139 induces destruction of villi, microvilli and lining epithelium with exposure of crypts of Lieberkuhn.
In our previous study, complete protection was observed in rabbit immunized with 1 × 1010 CFU of live attenuated VCUSM21P vaccine against challenge with 1 × 109 CFU Vibrio cholerae O139. In the present study, we investigated whether the vaccines can effectively protect immunized animals from any pathologic changes using histological, immunohistochemical and ultrastructural techniques. Severe pathology is evident in wild type injected ileum in non-immunized, showing extensive villous destruction, edema, necrosis and inflammation with infiltration of large numbers of inflammatory cells, extensive damage to the villi and microvilli with pore formation. Histology of ileum injected with wild type in immunized rabbit shows no significant pathological changes except for a few inflammatory cells in lamina propria with mild edema in mucosa and submucosa. immunohistochemical staining revealed O139 antigens of wild type are seen in the lamina propria of edematous villi, muscularis mucosa and submucosa with weak presence in the muscle coat in non-immunized rabbit after challenged with wild type in non-immunized rabbits, but in immunized rabbit localisation of the O139 LPS antigen is seen at the tips of the intact villi, within lamina propria and muscularis mucosa only. These observations suggest that the vaccine can effectively protect animals from any pathologic changes and eliminate V. cholerae O139 from the immunized animals.
Pathogens from the Vibrio and Aeromonas genera often cause detrimental effects to the aquaculture sector. Previously, antibiotics was used to resolve the infections, but this caused the spread of antibiotic resistant bacteria and antibiotic resistance genes into the environment. As an approach to address this issue, probiotic bacteria were introduced to improve the hosts' microbiome, disease protection, health condition, growth efficiency, feed consumption, stress response and general vigour. However, reports showed that some commercially available probiotics were restricted to a small number of microbial species and there are inconsistencies concerning its effectiveness. Hence, the aim of this study was to isolate and evaluate new Bacillus spp. from the gut of giant freshwater prawn as potential probiotics. Three Bacillus spp. isolates, Bacillus subtilis FS6 (MZ960135), Bacillus velezensis FS26 (MZ960133) and Bacillus pumilus FS97 (MZ960136) were characterised, and in vitro testing showed good probiotic properties which can help in dealing with diseases in aquaculture. Among the Bacillus spp., Bacillus velezensis FS26 showed higher antimicrobial activity towards Aeromonas hydrophila LMG 13658 and Aeromonas veronii clone DK-A. veronii-27 at 23.7 mm and 25 mm, respectively. Bacillus subtilis FS6 and Bacillus velezensis FS26 resulted in good adherence to both xylene and chloroform hydrocarbons. The Bacillus spp. isolated displayed high survivability towards 0.3% bile salt and exhibited amylase, protease, and lipase activities. Thus, the isolated Bacillus spp. are considered safe based on the sensitivity analysis towards antibiotics and γ-haemolytic activity.
Bacillus velezensis FS26 is a bacterium from the genus Bacillus that has been proven as a potential probiotic in aquaculture with a good antagonistic effect on Aeromonas spp. and Vibrio spp. Whole-genome sequencing (WGS) allows a comprehensive and in-depth analysis at the molecular level, and it is becoming an increasingly significant technique in aquaculture research. Although numerous probiotic genomes have been sequenced and investigated recently, there are minimal data on in silico analysis of B. velezensis as a probiotic bacterium isolated from aquaculture sources. Thus, this study aims to analyse the general genome characteristics and probiotic markers from the B. velezensis FS26 genome with secondary metabolites predicted against aquaculture pathogens. The B. velezensis FS26 genome (GenBank Accession: JAOPEO000000000) assembly proved to be of high quality, with eight contigs containing 3,926,371 bp and an average G + C content of 46.5%. According to antiSMASH analysis, five clusters of secondary metabolites from the B. velezensis FS26 genome showed 100% similarity. These clusters include Cluster 2 (bacilysin), Cluster 6 (bacillibactin), Cluster 7 (fengycin), Cluster 8 (bacillaene), and Cluster 9 (macrolactin H), which signify promising antibacterial, antifungal, and anticyanobacterial agents against pathogens in aquaculture. The probiotic markers of B. velezensis FS26 genome for adhesion capability in the hosts' intestine, as well as the acid and bile salt-tolerant genes, were also detected through the Prokaryotic Genome Annotation System (Prokka) annotation pipeline. These results are in agreement with our previous in vitro data, suggesting that the in silico investigation facilitates establishing B. velezensis FS26 as a beneficial probiotic for use in aquaculture.
Bacteriocin-like inhibitory substances (BLIS) produced by Lactococcus lactis Gh1 had shown antimicrobial activity against Listeria monocytogenes ATCC 15313. Brain Heart Infusion (BHI) broth is used for the cultivation and enumeration of lactic acid bacteria, but there is a need to improve the current medium composition for enhancement of BLIS production, and one of the approaches is to model the optimization process and identify the most appropriate medium formulation. Response surface methodology (RSM) and artificial neural network (ANN) models were employed in this study. In medium optimization, ANN (R2 = 0.98) methodology provided better estimation point and data fitting as compared to RSM (R2 = 0.79). In ANN, the optimal medium consisted of 35.38 g/L soytone, 16 g/L fructose, 3.25 g/L sodium chloride (NaCl) and 5.40 g/L disodium phosphate (Na2HPO4). BLIS production in optimal medium (717.13 ± 0.76 AU/mL) was about 1.40-fold higher than that obtained in nonoptimised (520.56 ± 3.37 AU/mL) medium. BLIS production was further improved by about 1.18 times higher in 2 L stirred tank bioreactor (787.40 ± 1.30 AU/mL) as compared to that obtained in 250 mL shake flask (665.28 ± 14.22 AU/mL) using the optimised medium.
Antibacterial peptides or bacteriocins produced by many strains of lactic acid bacteria have been used as food preservatives for many years without any known adverse effects. Bacteriocin titres can be modified by altering the physiological and nutritional factors of the producing bacterium to improve the production in terms of yield and productivity. The effects of culture conditions (initial pH, inoculum age and inoculum size) and medium compositions (organic and inorganic nitrogen sources; carbon sources) were assessed for the production of bacteriocin-like inhibitory substances (BLIS) by Lactococcus lactis Gh1 in shake flask cultures. An inoculum of the mid-exponential phase culture at 1% (v/v) was the optimal age and size, while initial pH of culture media at alkaline and acidic state did not show a significant impact on BLIS secretion. Organic nitrogen sources were more favourable for BLIS production compared to inorganic sources. Production of BLIS by L. lactis Gh1 in soytone was 1.28-times higher as compared to that of organic nitrogen sources ((NH4)2SO4). The highest cell concentration (XmX = 0.69 ± 0.026 g·L-1) and specific growth rate (μmax = 0.14 h-1) were also observed in cultivation using soytone. By replacing carbon sources with fructose, BLIS production was increased up to 34.94% compared to BHI medium, which gave the biomass cell concentration and specific growth rate of 0.66 ± 0.002 g·L-1 and 0.11 h-1, respectively. It can be concluded that the fermentation factors have pronounced influences on the growth of L. lactis Gh1 and BLIS production. Results from this study could be used for subsequent application in process design and optimisation for improving BLIS production by L. lactis Gh1 at larger scale.
Bamboo shoot crude polysaccharides (BSCP) extracted from the shoots of Gigantochloa levis gave about 3.27 ± 0.18% on dry basis and a very minute percentage of protein (0.02 ± 0.01%). The molecular weight of BSCP estimated by gel chromatography was found to be around 7.49 × 103 Da, while the molecular weights of purified fractions (F1 to F5) were around 1550.96, 1471.63, 1685.78, 1691.61 and 1551.67 Da, respectively. The FTIR spectrum of BSCP revealed the possibility that the extract contains β-glucan, which can be considered a valuable compound for the medical and food industries. These relate to the resistance of BSCP towards artificial human gastric juice which is more than 99%. Prebiotic activity tested using BSCP as a carbon source showed significant increase in the growth of B. animalis ATCC 1053, B. longum BB 536 and L. acidophilus ATCC 4356 as compared to the use of FOS. Survivality of S. choleraesuis JCM 6977 was found to be slower in both BSCP and FOS. Study conducted reflects a good sign for the BSCP to be exploited as a promising prebiotic.
Corn silk (Stigma maydis) is an important herb used traditionally by the Chinese, and Native Americans to treat many diseases. It is also used as traditional medicine in many parts of the world such as Turkey, United States and France. Its potential antioxidant and healthcare applications as diuretic agent, in hyperglycemia reduction, as anti-depressant and anti-fatigue use have been claimed in several reports. Other uses of corn silk include teas and supplements to treat urinary related problems. The potential use is very much related to its properties and mechanism of action of its plant's bioactive constituents such as flavonoids and terpenoids. As such, this review will cover the research findings on the potential applications of corn silk in healthcare which include its phytochemical and pharmacological activities. In addition, the botanical description and its toxicological studies are also included.
An Aqueous Two-Phase System (ATPS) was employed for the first time for the separation and purification of pectinase from mango (Mangifera Indica Cv. Chokanan) peel. The effects of different parameters such as molecular weight of the polymer (polyethylene glycol, 2,000-10,000), potassium phosphate composition (12-20%, w/w), system pH (6-9), and addition of different concentrations of neutral salts (0-8%, w/w) on partition behavior of pectinase were investigated. The partition coefficient of the enzyme was decreased by increasing the PEG molecular weight. Additionally, the phase composition showed a significant effect on purification factor and yield of the enzyme. Optimum conditions for purification of pectinase from mango peel were achieved in a 14% PEG 4000-14% potassium phosphate system using 3% (w/w) NaCl addition at pH 7.0. Based on this system, the purification factor of pectinase was increased to 13.2 with a high yield of (97.6%). Thus, this study proves that ATPS can be an inexpensive and effective method for partitioning of pectinase from mango peel.
A 'Heat treatment aqueous two phase system' was employed for the first time to purify serine protease from kesinai (Streblus asper) leaves. In this study, introduction of heat treatment procedure in serine protease purification was investigated. In addition, the effects of different molecular weights of polyethylene glycol (PEG 4000, 6000 and 8000) at concentrations of 8, 16 and 21% (w/w) as well as salts (Na-citrate, MgSO₄ and K₂HPO₄) at concentrations of 12, 15, 18% (w/w) on serine protease partition behavior were studied. Optimum conditions for serine protease purification were achieved in the PEG-rich phase with composition of 16% PEG6000-15% MgSO₄. Also, thermal treatment of kesinai leaves at 55 °C for 15 min resulted in higher purity and recovery yield compared to the non-heat treatment sample. Furthermore, this study investigated the effects of various concentrations of NaCl addition (2, 4, 6 and 8% w/w) and different pH (4, 7 and 9) on the optimization of the system to obtain high yields of the enzyme. The recovery of serine protease was significantly enhanced in the presence of 4% (w/w) of NaCl at pH 7.0. Based on this system, the purification factor was increased 14.4 fold and achieved a high yield of 96.7%.
Response surface methodology (RSM) using a central composite design (CCD) was employed to optimize the conditions for extraction of serine protease from kesinai (Streblus asper) leaves. The effect of independent variables, namely temperature (42.5,47.5, X₁), mixing time (2-6 min, X₂), buffer content (0-80 mL, X₃) and buffer pH (4.5-10.5, X₄) on specific activity, storage stability, temperature and oxidizing agent stability of serine protease from kesinai leaves was investigated. The study demonstrated that use of the optimum temperature, mixing time, buffer content and buffer pH conditions protected serine protease during extraction, as demonstrated by low activity loss. It was found that the interaction effect of mixing time and buffer content improved the serine protease stability, and the buffer pH had the most significant effect on the specific activity of the enzyme. The most desirable conditions of 2.5 °C temperature, 4 min mixing time, 40 mL buffer at pH 7.5 was established for serine protease extraction from kesinai leaves.
Lipase is one of the more important enzymes used in various industries such as the food, detergent, pharmaceutical, textile, and pulp and paper sectors. A novel aqueous two-phase system composed of surfactant and xylitol was employed for the first time to purify lipase from Cucurbita moschata. The influence of different parameters such as type and concentration of surfactants, and the composition of the surfactant/xylitol mixtures on the partitioning behavior and recovery of lipase was investigated. Moreover, the effect of system pH and crude load on the degree of purification and yield of the purified lipase were studied. The results indicated that the lipase was partitioned into the top surfactant rich phase while the impurities partitioned into the bottom xylitol-rich phase using an aqueous two phase system composed of 24% (w/w) Triton X-100 and 20% (w/w) xylitol, at 56.2% of tie line length (TLL), (TTL is one of the important parameters in this study and it is determined from a bimodal curve in which the tie-line connects two nodes on the bimodal, that represent concentration of phase components in the top and bottom phases) and a crude load of 25% (w/w) at pH 8.0. Recovery and recycling of components was also measured in each successive step process. The enzyme was successfully recovered by the proposed method with a high purification factor of 16.4 and yield of 97.4% while over 97% of the phase components were also recovered and recycled. This study demonstrated that the proposed novel aqueous two phase system method is more efficient and economical than the traditional aqueous two phase system method for the purification and recovery of the valuable enzyme lipase.