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The ichthyodiversity of Uttar Dinajpur district of West Bengal, India was assessed in the current study. The district is adorned by various rivers, feeder channels, dams, bills, ponds, reservoirs and thus contributes significantly to the aquatic productivity of the state. A field survey was conducted in randomly chosen fish markets of nine community development blocks of Uttar Dinajpur. The study found a large ichthyodiversity in the area including 76 fish species from 26 families. With 28 distinct species, the Cyprinidae family dominated. Thirteen, globally endemic, freshwater fish species were also observed during the study. Clarias magur, one of the endangered species, is also available in the district. The overall physicochemical parameters of the culture waters of Uttar Dinajpur district are ideal for freshwater fish farming. Geo-Spatial analysis discloses the fragmentation of natural water bodies in the district. The district consists of 10 registered and 7 unregistered hatcheries which are playing a vital role in the restoration of various indigenous fishes and provide accommodation to the exotic fishes. Uttar Dinajpur has many perennial freshwater bodies. Thus, the region holds a high potentiality in the aquaculture sector. Efficient management, proper knowledge, and scientific cultivation can greatly influence aquatic productivity and diversity. Simultaneously, the restoration of indigenous fishes has become a surging need of the hour. The current study pointed out the fact that the indigenous Clarias magur has often been substituted by C. gariepinus which may cause a potential threat to biodiversity. Some traders promote this banned exotic species through illegal farming. As a result, the native, nutrient rich C. batrachus is now becoming critically endangered. The existing endemic fishes must urgently be conserved to uphold the diversification of the ichthyofauna in the district. [ABSTRACT FROM AUTHOR]

An acidophilic α-amylase from Aspergillus niger RBP7 was purified after solid state fermentation on potato peel substrate. Molecular mass of the purified α-amylase was 37.5 kDa and it exhibited 1.4 mg/ml and 0.992 μ/mol/min Km and Vmax values, respectively. The enzyme was stable in the pH range from 2.0 to 6.0, at high NaCl concentration (3 M) and at temperatures between 40 °C and 70 °C. The enzyme showed an optimal activity at pH 3.0 and at 45 °C. The enzyme was inhibited by Hg2+ and was stable in the presence of different surfactants (Tween 60, Tween 80, and SDS at 1% level) and different inhibitory reagents (β-mercaptoethanol, phenylmethylsulfonyl fluoride, and sodium azide). This acidophilic amylase enzyme can digest heterogeneous food materials, i.e. the mixture of rice, fish, bread and curry with comparable activity to the commercial diastase enzymes available. [ABSTRACT FROM AUTHOR]

Chromate reductase production by a bacterial isolate CSB 9 has been optimized to a high titer in the present investigation. The bacterium isolated previously from a chromium contaminated site and identified as Bacillus amyloliquefaciens following biochemical and 16S rRNA gene sequencing, was evaluated for chromate reductase production. Chromate reductase activity of B. amyloliquefaciens (CSB 9) was associated with the contribution of extracellular enzymes under the influence of various physico-chemical parameters. In presence of 50 µM of Cr(VI) concentration, the bacterial growth exhibited 8 h of lag phase, 8–32 h of log phase and stationary phase upto 48 h. The maximum chromate reductase production was achieved in the presence of 50 µM of Cr(VI); 0.5% (w/v) of glucose; 1% (w/v) of trypton; 0.5% (w/v) of Na 2 HPO 4 ; 0.5% (w/v) KNO 3 ; 0.5% (w/v) KCl and 0.5% (w/v) thiamine as source of vitamin with the initial medium pH of 7.0 and incubation at 35 °C under shaking condition (100 rpm). In optimized conditions, the chromate reductase production was enhanced to a significant level of 3.67±0.014 U ml −1 as compared to unoptimized condition (2.37±0.029 U ml −1 ) with decrease in time from 20 h (late log phase) under unoptimized condition to 16 h under optimized condition. This communication elucidates the enhanced production of extracellular chromate reductase from a newly isolated bacterium B. amyloliquefaciens from chromite mine soil under optimized conditions which can be potentially exploited for biotechnological application. [ABSTRACT FROM AUTHOR]

Lysinibacillus sphaericus PKA17, Bacillus cereus PKA18 and Bacillus thuringiensis PKA19, isolated from the intestine of adult indigenous magur (Clarias magur), were evaluated as putative probiotics for the cultivation of C. magur fingerlings. A total of 180 magur fingerlings (average weight 4.01 ± 0.01 g) were randomly distributed into four dietary groups in triplicate. The fingerlings were cultivated for 120 days into continuous-flow experimental rectangular cemented tanks (195 × 105 × 90 cm3; 1600 l; 5 cm bottom mud). Probiotics were mixed in feed (PT1: 2 × 106 L. sphaericus PKA17 cells; PT2: 2 × 106 B. cereus PKA18 cells; PT3: 2 × 106 B. thuringiensis PKA19 cfu/kg of basal feed where, PT = Probiotic treated) and fed to different dietary groups of fish. However, the control feed comprises of basal ingredients, and was not supplemented with any bacterial isolate. Fish carcass composition revealed significantly (p < 0.05) higher amounts of carbohydrate (2.8 ± 0.06 g kg−1), iron (2.21 ± 0.01 mg 100 g−1), fat-soluble vitamins and amino acid in fish fed PT1 than other groups. Fish fed PT1 feed also displayed a considerably higher protein efficiency ratio (2.05 ± 0.01) and lower feed conversion ratio (1.23 ± 0.01). Higher carcass protein content (164.9 ± 0.23 g kg−1) was observed in fish fed PT3 feed followed by PT1 and PT2. Fish fed probiotic-supplemented feed (PT1, PT2, and PT3) showed higher amounts of high-density lipoprotein and calcium than the control-fed fish. High survivability was observed in fish fed probiotic-feed compared to the control group. The results suggest that feed (PT1, PT2, PT3) incorporated with these probiotics might enhance the growth of C. magur in captivity, which may promote the cultivation of this endangered species. [ABSTRACT FROM AUTHOR]

Haria is a rice-based fermented beverage that is popular among tribal and low income people in lateritic West Bengal and East-Central India. The principal ingredient of this beverage is low grade boiled rice (Oryza sativa L.), which is mixed with a traditional starter, called bakhar, and fermented within a heat-sterilized earthen pot for 3-4 days. The main aim of this study was to investigate the ethnobotanical importance and traditional process of haria preparation. The method adopted for this study was based on interactive questionnaires and laboratory experiments. It was found that the pH decreased during the course of fermentation with increased titratable acidity of 1.42%. The alcohol content was 2-3% (v/v) in the consumable beverages. This documentation will be useful for further exploitation of haria as a health drink. [ABSTRACT FROM AUTHOR]

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 (126.05 and 873.23 folds, 1.31 and 1.44 gdi) were increased whereas total anaerobes (7.01 x 10(4) and 8.84 x 10(3) 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.

In 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.

Collagen, a major component of native extracellular matrix, has diverse biomedical applications. However, its application is limited due to lack of cost-effective production and risk of disease transmission from bovine sources currently utilized. This study describes fabrication and characterization of nano/micro fibrous scaffolds utilizing collagen extracted from fresh water fish origin. This is the first time collagen extracted from fresh water fish origin was studied for their biocompatibility and immunogenicity. The nano/micro fibrous collagen scaffolds were fabricated through self-assembly owing to its amphiphilic nature and were subsequently cross-linked. In vitro degradation study revealed higher stability of the cross-linked scaffolds with only ~50% reduction of mass in 30 days, while the uncross-linked one degraded completely in 4 days. Further, minimal inflammatory response was observed when collagen solution was injected in mice with or without adjuvant, without significant dilution of sera. The fish collagen scaffolds exhibited considerable cell viability and were comparable with that of bovine collagen. SEM and fluorescence microscopic analysis revealed significant proliferation rate of cells on the scaffolds and within 5 days the cells were fully confluent. These findings indicated that fish collagen scaffolds derived from fresh water origin were highly biocompatible in nature., (Copyright © 2012 Wiley Periodicals, Inc.)