Screening of gastrointestinal bacteria of Indian major carps for a candidate probiotic species for aquaculture practices     

Sukanta K Nayak  Subhas C Mukherjee 《Aquaculture Research》2011,42(7):1034-1041

Probotic selection could be detrimental for the success of aquaculture practices. While, in most of the cases emphasis is given to the production of antibacterial compounds, and in vitro inhibitory activities of a bacterium for choosing a probiotic strain, however, other criteria like non‐antibiotic resistant, non‐haemolytic nature and non‐pathogenic potentiality of probiotic strain are often overlooked. We have screened gastrointestinal bacteria isolated from all the three species of Indian major carps viz., Labeo rohita, Catla catla and Cirrhinus mrigala for a suitable probiotic. Bacteria like Aeromonas (Aeromonas species, A. hydrophila), Micrococcus, Corynebacterium, Plesiomonas, Bacillus (Bacillus species, B. subtilis) and Pseudomonas (Pseudomonas species, P. aeruginosa) exhibited antibacterial activities against different pathogens. Among these, B. subtilis was found to grow at a wider range of temperatures, pH and salt concentrations and was non‐haemolytic, non‐antibiotic resistant, non‐pathogenic and inhibited all the tested primary and secondary pathogens. Dietary supplementation of the bacteria at 10⁸ CFU g^?1 feed also enhanced the growth of Indian major carp, L. rohita. Based upon these characteristics, we aimed to develop a suitable probiotic for aquaculture practices.  相似文献   

Identification of transposable element markers associated with yield and quality traits from an association panel of independent mutants in peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.)     

A. A. Hake  K. Shirasawa  A. Yadawad  S. N. Nayak  S. Mondal  A. M. Badigannavar  H. L. Nadaf  M. V. C. Gowda  R. S. Bhat 《Euphytica》2017,213(12):283

To identify marker–trait associations (MTAs) for yield and quality traits in peanut, genic and nongenic Arachis hypogaea transposable element (AhTE) markers were employed in a population consisting of independent mutants from several parents. The population was field-evaluated during the rainy seasons of 2014 and 2015, and genotyped with 110 AhTE markers to check the polymorphisms for AhMITE1 transposition. The gene diversity index ranged from 0.00 to 0.50 with average of 0.35, indicating low to moderate genetic diversity in the population. Diversity analysis indicated the grouping of mutants derived from each parent in respective subgroups. Marker–trait association analysis for 110 markers and 40 traits resulted in 132 highly significant MTAs, represented by 58 AhTE markers for 39 traits. Nutritional traits recorded the highest number of MTAs (38), followed by agronomic traits (35), productivity traits (31), foliar disease resistance (23), and taxonomic traits (5). Seventeen MTAs with phenotypic variance explained (PVE) value above 50 % were observed for resistance to late leaf spot (LLS) and rust, plant height, and pod width. The genic and nongenic AhTE markers associated with the above traits were analyzed for their genomic location and functional annotation so that the significance of these loci can be analyzed in the future.  相似文献   

Antimicrobial activity of partially characterized analytes from Bacillus pumilus(B2)          下载免费PDF全文

Sanghamitra Nayak  Chalor Limsuwan  Niti Chichurd  Kai‐J. Kühlmann  Supranee Pungpang 《Aquaculture Research》2017,48(11):5606-5613

This study was carried out to characterize the antimicrobial substance produced by the strain of Bacillus pumilus (B2) obtained from Novozymes Biologicals Inc. to compare its antimicrobial activity by agar well diffusion assay and bacteriocin activity assay via critical dilution method against seven different strains of Vibrio spp., specifically V. alginolyticus (A01), V. cholerae (C01), V. fluvialis (F01, F02), V herveyii (H), V. mimicus (M01), V. parahaemolyticus (P01) and V. vulnificus (V01, V02). All Vibrio spp. were isolated from the hemolymph and intestine of the white faeces disease‐infected moribund pacific white‐leg shrimp Litopenaeus vannamei (Boone 1931) and one strain (V. harveyi) from its diseased postlarva. The cell‐free neutralized supernatant (CFNS) of B2 showed moderate thermo‐stability being stable up to 70°C for 60 min with, however, reducing activity above 80°C for 20 min. B2 antimicrobials showed a stable activity within the pH ranging from 6 to 10 at room temperature and at 4°C, while residual antimicrobial activity of crude CFNS showed tolerance to salinity up to 7% of sodium chloride below 4°C. No B2 activity was obtained while exposed to proteolytic enzyme, such as proteinase k and pepsin, while its activity kept stable exposed to lipase. Initial B2 characterization for antimicrobial substance in CFNS revealed proteinaceous in nature owing to activity loss against proteolytic enzymes and no lipid moiety activity against lipase, which could be categorized as bacteriocin‐like inhibitory substance having potential application against several strains of Vibrio spp. in aquaculture.  相似文献   

Effect of Nutrient Application on Growth,Metabolic and Enzymatic Activities of Rice Seedlings During Flooding Stress and Subsequent Re‐Aeration          下载免费PDF全文

B. Lal  L. Rath  D. Haldar  B. B. Panda  R. Raja  M. Shahid  R. Tripathi  P. Bhattacharyya  S. Mohanty  A. K. Nayak 《Journal of Agronomy and Crop Science》2015,201(2):138-151

The impact of submergence on the allometry, changes in metabolic activities and antioxidant enzymes during oxidative stress in four Indica rice varieties namely IR‐20, IR‐64 Sub1, Swarna Sub1 and Savitri Sub1 was studied. The differential response of flooding under clear and turbid water with different nutrient application schedules was also examined during and after 12 days of complete submergence. Submergence substantially reduced allometric parameters and the activities of antioxidant enzymes but increased the % change in chlorophyll, soluble sugars and malondialdehyde (MDA) across cultivars with drastic effects on IR‐20. Turbid water resulted in higher leaf senescence, lodging, higher depletion of chlorophyll and soluble sugars because of poor light transmission. Pre‐submergence N application resulted in higher lodging, leaf senescence and higher MDA level but depletion of chlorophyll and NSC leading to higher % change over prior to submergence. Basal P application reduced the senescence and lodging, whereas increased the antioxidant enzyme activities. Foliar spray of post‐submergence N with basal P improved the retention and regain of chlorophyll, soluble sugar and increased the dry matter, leaf area and root shoot ratio. Crop establishment could therefore be enhanced in areas where untimely flooding is anticipated by applying basal P and foliar spray of urea after desubmergence.  相似文献   

Re‐evaluating the biophysical and technologically attainable potential of topsoil carbon sequestration in China's cropland     

K. Cheng  J. Zheng  D. Nayak  P. Smith  G. Pan 《Soil Use and Management》2013,29(4):501-509

To assess the topsoil carbon sequestration potential (CSP) of China's cropland, two different estimates were made: (i) a biophysical potential (BP) using a saturation limit approach based on soil organic carbon (SOC) accumulation dynamics and a storage restoration approach from the cultivation‐induced SOC loss, and (ii) a technically attainable potential (TAP) with a scenario estimation approach using SOC increases under best management practices (BMPs) in agriculture. Thus, the BP is projected to be the gap in recent SOC storage to either the saturation capacity or to the SOC storage of uncultivated soil, while the TAP is the overall increase over the current SOC storage that could be achieved with the extension of BMPs. The recent mean SOC density of China's cropland was estimated to be 36.44 t/ha, with a BP estimate of 2.21 Pg C by a saturation approach and 2.95 Pg C by the storage restoration method. An overall TAP of 0.62 Pg C and 0.98 Pg C was predicted for conservation tillage plus straw return and recommended fertilizer applications, respectively. This TAP is comparable to 40–60% of total CO₂ emissions from Chinese energy production in 2007. Therefore, carbon sequestration in China's cropland is recommended for enhancing China's mitigation capacity for climate change. However, priority should be given to the vast dry cropland areas of China, as the CSP of China is based predominantly on the dry cropland.  相似文献   

Long‐term effects of fertilizer and manure applications on soil quality and yields in a sub‐humid tropical rice‐rice system     

M. Shahid  A. K. Nayak  A. K. Shukla  R. Tripathi  A. Kumar  S. Mohanty  P. Bhattacharyya  R. Raja  B. B. Panda 《Soil Use and Management》2013,29(3):322-332

Widespread yield stagnation and productivity declines in the rice–rice cropping system have been reported and many of the associated issues are related to soil quality. A long‐term experimental study was initiated in 1969 to assess the impact of continuous cultivation of rice as a single crop grown in wet as well as dry seasons using varying levels of chemical fertilizer and manure applications on soil quality indicators (physical, chemical and biological), a sustainable yield index (SYI) and a soil quality index (SQI). The treatments comprised chemical fertilizers and farmyard manure (FYM) either alone or in combination viz. control, N, NP, NK, NPK, FYM, N+FYM, NP+FYM, NK+FYM and NPK+FYM, laid out in a randomized complete block design with three replications. Soil samples were collected after the wet season rice harvest in 2010 and were analysed for physical, chemical and biological indicators of soil quality. A SYI based on long‐term yield data and SQI using principal component analysis (PCA) and nonlinear scoring functions were calculated. Application of NPK fertilizers in combination with FYM significantly increased the average grain yield of rice in both wet and dry seasons and enhanced the sustainability of the system compared to the control and plots in receipt of fertilizers. The SYI for the control was higher in the wet season than in the dry one, whereas the reverse was true for NPK+FYM treatment. The value of the dimensionless SQI varied from 1.46 in the control plot to 3.78 in the NPK+FYM one. A greater SYI and SQI in the NPK+FYM treatment demonstrated the importance of using a chemical fertilizer in combination with FYM. For the six soil quality indicators selected as a minimum data set (MDS), the contribution of DTPA‐Zn, available‐N and soil organic carbon to the SQI was substantial ranging from 59.4 to 85.7 per cent in NPK+FYM and control plots, respectively. Thus, these soil parameters could be used to monitor soil quality in a subhumid tropical rice–rice system.  相似文献   

Bioactivity of antioxidants in extruded products prepared from purple potato and dry pea flours     

Nayak B  Liu RH  Berrios Jde J  Tang J  Derito C 《Journal of agricultural and food chemistry》2011,59(15):8233-8243

Measuring antioxidant activity using a biologically relevant assay adds important evidence to aid in understanding the role of phytochemicals based on data from in vivo and chemical assays of extrusion processed purple potato and pea flours. A cellular antioxidant activity assay could provide biologically relevant information on bioactive compounds in raw as well as processed food products. The objective of this study was to investigate the complete phytochemical profiles, antioxidant activity, cellular antioxidant activity, and their contribution to bioactivity in purple potato flour, dry pea flour, raw formulations, and extrusion cooked products prepared with the above ingredients. The free fraction of extracts contributed 68, 64, and 88% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in purple potato flour (PPF). Similarly, extracts in the free fraction contributed 87, 86, and 64% to total phenolics, total antioxidant activity (ORAC value), and total flavonoids, respectively, in dry pea flour (DPF). The amount of total phenolics and total flavonoids in purple potato flour and the antioxidant activity of PPF and DPF were comparable to published data. However, a higher amount in the total flavonoids and lower in the total phenolics of DPF were observed. Caffeic, p-coumaric, and ferulic acids were mostly observed in the bound extracts of raw formulations as in the extrudates, whereas chlorogenic acid was predominant in the free extracts. The extruded products had significantly higher (p < 0.05) content of total phenolics, ORAC antioxidant activity, and flavonoids, compared to the raw formulations. Extrusion processing increased the cellular antioxidant activity of the extrudates prepared from 35:65 and 50:50 PPF/DPF (w/w) of ingredients compared with control raw formulations in a dose-dependent manner. Increase of PPF significantly increased (p < 0.05) the cellular antioxidant activity of 35-50% PPF formulations.  相似文献   

Review on small ruminant conservation status and prospects in India     

Pathak  Prajwalita  Nayak  Vivek Kumar  Sinha  Rebeka  Ganaie  Bilal Ahmad 《Tropical animal health and production》2020,52(6):2817-2827

Tropical Animal Health and Production - Small ruminants always play a major role in the agricultural economy of India. They provide livelihoods to numerous small and marginal farmers. The diversity...  相似文献   

Determining changes in the distribution and abundance of a Rhyzopertha dominica phosphine resistance allele in farm grain storages using a DNA marker     

Ramandeep Kaur  Emily V Daniels  Manoj K Nayak  Paul R Ebert  David I Schlipalius 《Pest management science》2013,69(6):685-688

  相似文献   

Campylobacter detection in commercial turkeys     

Kiess AS  Kenney PB  Nayak RR 《British poultry science》2007,48(5):567-572

1. Frequency of Campylobacter detection was monitored in three flocks of turkeys. The effect of week of production was evaluated for hens in flocks 1 and 2, and the effect of week, gender and litter (fresh or used) was assessed for flock 3. 2. Gastrointestinal tracts, poult box liners, drinkers and faecal droppings were sampled. Conventional microbiological procedures were used to isolate and identify the presence of Campylobacter. Campylobacter latex agglutination tests were used for confirmation. 3. Peak colonisation occurred at approximately 3 weeks of production. Frequency of Campylobacter isolation from bird sources paralleled isolation from waterers. Frequency of detection from birds placed on used litter was lower than detection from birds placed on fresh litter (2% vs 58%). Gender did not affect frequency of detection. 4. Minimising peak colonisation at 3 weeks and managing litter are opportunities to reduce the occurrence of this organism in turkeys.  相似文献