Parametric optimalization of submerged fermantation conditions for xylanase production Bacillus cereus BSA1 through Taguchi Methodology

Extracellular xylanase production of Bacillus cereus BSA1 was optimized under submerged fermentation using Taguchi orthogonal array (OA). An L18 layout of OA was constructed at three-levels of six factors, i.e. temperature, pH, and xylan, Na2HPO4, NH4NO3 and NaCl concentrations, influencing the xylanase synthesis. The enzyme production was studied in 18 parallel batch systems using different levels of each factor. The results were processed with Qualitek-4 software using ‘bigger is better’ quality character, and combination of 35 oC; pH 6.0; and xylan 0.5; NH4NO3 0.5, Na2HPO4, 0.1; NaCl 0.05 concentrations (in w/v %) with a predictive xylanase production of 7.404 U/ml was obtained. Fermentation experiment was performed for further validating the statistical output, and it resulted 10.24% in the xylanase yield (from 6.44 U/ml to 7.10 U/ml) as compared to one variable at a time (OVAT) design. Interaction effects of the factors individually and in combination can be evaluated by using Taguchi method design of experiment

Effect of microbial load on the condition index of the edible oyster, Saccostrea cucullata in the Sundarbans, India

The effect of microbial load on the condition Index of the edible oyster, Saccostrea cucullata were analysed on monthly basis during 2010 and 2011 from the three different stations (Namkhana, Frasergaunge and Sajnekhali) of Indian Sundarbans. The results showed significant variation with respect to microbial load between stations and seasons, which is reflected in the tissue of edible oyster. Significant positive correlations were observed between microbial load of the ambient environment and the tissue system of oyster. The Condition Index of the oyster species also exhibited negative correlation with the microbial load of oyster tissue, which confirms the negative stress induced by microbes on the growth and survival of the species

Arsenic biosorption by mucilaginous seeds of Hyptis suaveolens (L.) Poit

577-581Hyptis suaveolens seeds could serve as natural immobilized source of agriculturally based polysaccharide. Maximum adsorption capacity (6 gl⁻¹) of the seeds for arsenic adsorption has been found at pH 3.5 - 4.5. Among the tested interfering common metal ions, Ca⁺⁺, Mg⁺⁺ and Cl⁻ decreased adsorption rate about 48%, 54% and 30% respectively, whereas Zn⁺⁺ and Co⁺⁺ ions have no significant effect. Adsorption isotherm studies revealed a better correlation with Langmuir isotherm plot

Biological and Photocatalytic Activity of Silver Nanoparticle Synthesized from Ehretia laevis Roxb. Leaves Extract

Silver nanoparticles were synthesized from Ehretia laevis Roxb. leaf extract by one-step green synthesis method. The nanoparticles were crystalline in nature, spherical shaped with 25 to 35 nm diameter. The aim of this study was the synthesis and characterization of silver nanoparticles from Ehretia laevis Roxb., and the evaluation of their antimicrobial, anticancer, larvicidal and methylene blue dye degradation efficiency. The nanoparticles showed antimicrobial, larvicidal and cytotoxic activity. At a concentration of 25 μg/mL, it killed 70 ± 10.24% of Culex quinquefasciatus larvae after 72 h treatment. The median lethal concentration of the nanoparticles against HeLa, human cervical cancer cells, and MCF-7 human breast cancer cells, were calculated to 12.7 μg/mL and 14.5 μg/mL, respectively. The synthesized nanoparticles degraded Congo red ~ 85% within 8 h at a concentration of 200 μg/mL. Possible application of the synthesized nanoparticles are water purifying agent in presence of sunlight

Effect of microbial load on the condition index of the edible oyster, Saccostrea cucullata in the Sundarbans, India

The effect of microbial load on the condition Index of the edible oyster, Saccostrea cucullata were analysed on monthly basis during 2010 and 2011 from the three different stations (Namkhana, Frasergaunge and Sajnekhali) of Indian Sundarbans. The results showed significant variation with respect to microbial load between stations and seasons, which is reflected in the tissue of edible oyster. Significant positive correlations were observed between microbial load of the ambient environment and the tissue system of oyster. The Condition Index of the oyster species also exhibited negative correlation with the microbial load of oyster tissue, which confirms the negative stress induced by microbes on the growth and survival of the species

Rapid screening of tannase producing microbes by using natural tannin

Use of natural tannin in the screening of tannase producing microbes is really promising. The present work describes about the possibility and integrity of the newly formulated method over the previously reported methods. Tannin isolated from Terminalia belerica Roxb. (Bahera) was used to differentiate between tanninolytic and nontanninolytic microbes. The method is simple, sensitive and superior for the rapid screening and isolation of tannase-producing microbes

Analysis of alteration of gut microbial population under the exposure of graded hyperbaric pressures: Application of metagenomic approach

960-968<span style="mso-bidi-language: HI" lang="EN-GB">Gastroenterological disorders are very common at hyperbaric conditions. The present study was conducted to find out the impact of gut flora on the gastrointestinal disorders created at such environmental circumstances. For this, male albino rat were exposed to graded hyperbaric pressures (915 and 1277 mmHg) and large intestinal content was examined for microbial composition using culture based and PCR-DGGE tools. After 30 day exposure, total aerobes (38.54 and 375.57 folds, 1.35 and 1.58 gdi) and E. coli <span style="mso-bidi-font-style: italic">(126.05 and 873.23 folds, 1.31 and 1.44 gdi) were increased whereas total anaerobes (7.01 × 104 and 8.84 × 103 folds, -1.56 and -1.39 gdi), Enterobacter spp. (-2.45 and -1.00 gdi) and Clostridium perfringens (12.88 and 54.16 folds, -1.38 and -1.75 gdi) were decreased significantly in respect to control after exposure of simulated hyperbaric pressures like at 915 and 1277 mmHg, respectively. Metagenomics study revealed an overall reduction in total microbial profile was noted than control at higher level hyperbaric pressure, i.e., 1277 mmHg air pressure for highest duration of exposure. Though, some new bands also appeared which indicated the expansion of dormant or new microbiota, Variation in the numbers of these newly dominated bacteria was correlated to dose and duration of hyperbaric treatment. The histological results clearly indicated that hyperbaric environment induced severe inflammation in the mucosal and submucosal layer of large intestine. Thus, the result suggest that hyperbaric pressure is an important exogenous factor that strongly modulated the intestinal morphology and microbial ecology, and induced several gastrointestinal ailments during hyperbarism. </span

Exploitation of fermented shrimp-shells hydrolysate as functional food: Assessment of antioxidant, hypocholesterolemic and prebiotic activities

924-934In the present study the bioactivities of chitooligosaccharides of fermented shrimp-shell hydrolysate (SSH) in respect to hypocholesterolemic, antioxidant and prebiotic activity were tested in male albino rat. Rats were treated with four different diets, viz., (i) cholesterol-rich (5%) basal diet (ChB), (ii) ChB+10% chitin, (iii) ChB+10% SSH and (iv) control group (without cholesterol). After 4 weeks of treatment, body mass index, liver weight, serum total cholesterol and LDL-cholesterol in groups (ii) and (iii) were decreased significantly than group (i). SSH supplementation significantly resists oxidative stress by reducing the thiobarbituric acid reactive substances and by increasing catalase, superoxide dismutase and free radical scavenging activity. The colonization of Lactobacillus and Bifidobacterium population in small and large intestine were more in group (iii) than other groups. Reduction of Clostridium perfringens population and non-significant changes of E. coli was also noted in SSH supplement group. Histological study revealed that the villus height and villus:crypt of the small intestine were increased significantly in SSH supplemented group (iii) without any diarrheal symptoms. The results demonstrated that the shrimp-shells hydrolysate has hypocholesterolemic effect, can resist lipid peroxidation and can influence the growth of health beneficial microbes, hence can be used as functional food for hypercholesterolemic patients. </span