Species composition of microzooplankton Tintinnid from the coastal waters of Digha, Bay of Bengal.

Tintinnid species distribution and hydrography were studied in the coastal waters of Digha during winter (November 2015) and summer (March 2016) seasons. Surface water samples were collected from 11 different stations from 0 to 10 km offshore with the help of a mechanized trawler. Parameters like tintinnid species enumeration, zooplankton biomass, phytoplankton concentration (total chlorophyll) and abundance, sea surface temperature (SST), pH, transparency, salinity, dissolved oxygen (DO), total phosphate, silicate and nitrate were analysed. A total of 20 different tintinnid species (16 agglomerated +4 non-agglomerated) belonging to 6 genera were recorded from the study area with seasonal variation in tintinnid diversity, i.e. higher in summer (total 2745 individual/l) compared to winter (total 1191 individual/l). Tintinnopsis was the most dominant genus during both the seasons, i.e. 2100 individual/l in summer and 727 individual/l in winter, contributing about 76 and 61% population for the respective seasons. The correlation between species and water quality parameters showed that Tintinnopsis sp. abundance was significantly regulated by nitrate concentration, salinity, dissolved oxygen, water transparency and pH. However, the mentioned hydrological parameters were not the only factors regulating the tintinnid abundance. Tintinnid abundance was also found to be positively related with transparency (r = 0.732) and salinity (r = 0.524) and moderately related with dissolved oxygen (r = 0.488) whereas strong negative relation (at p ≤ 0.05) was established between tintinnid abundance with nitrate (r = -0.681) and pH (r = -0.561). Bray-Curtis cluster analysis of tintinnid species showed more than 60% similarity. Shannon's diversity index (H'), Simpson's evenness index (D) and Margalef's species richness index were found to be higher in summer, i.e. 1.61, 0.729 and 1.612, compared to the winter season, i.e. 1.139, 0.597 and 1.268. k-dominance curve showed maximum abundance of Tintinnopsis baltica in winter and Tintinnopsis gracilis in summer. Principal component analysis (PCA) was analysed to find out the environmental variables affecting different tintinnid species diversity. A significant spatiotemporal variation in Tintinnid population distribution was observed from two-way ANOVA. The results reflect significant seasonal (F = 840.0), spatial (F = 47.3) and interactive variation (F = 71.2) among the ciliate microzooplankton at n = 66, p ≤ 0.001. High chlorophyll content and phytoplankton population in summer indicated that tintinnid diversity in the season was positively influenced by producer community in coastal waters of Digha.

Poultry feed based on protein hydrolysate derived from chrome-tanned leather solid waste: creating value from waste.

Leather industry generates huge amount of chrome-containing leather solid waste which creates major environment problems to tanners worldwide. Chrome-tanned leather solid waste is primarily chromium complex of collagen protein. The presence of chromium limits its protein application in animal feed industry. The purified protein hydrolysate with zero chromium could be used in poultry feed. In this study, an attempt has been made to assess performance of poultry with purified protein hydrolysate as a feed derived from chrome-tanned leather waste as partial replacement of soyabean meal as a sole source of protein for growing broiler chickens. Growth study was conducted to evaluate the effect of feeding protein hydrolysate on performance and physiochemical characteristics of meat of broiler chickens. Two experimental diets containing various levels of protein hydrolysate (EI-20 % and EII-30 %) were evaluated. The comparative study was performed as control with soyabean meal. Daily feed intake, body weight gain and feed conversion ratio were measured from day 8 to day 35. At the end of the study, birds were randomly selected and slaughtered to evaluate for physiochemical characteristics of meat. Diet had significant effects on feed intake and body weight gain. Birds fed with 20 and 30 % protein hydrolysate consumed 9.5 and 17.5 % higher amount of feed and gained 6.5 and 16.6 % higher than soyabean meal-fed birds. The current study produced evidence that protein hydrolysate can replace up to 75 % of soyabean meal in broiler diets without affecting either growth performance or meat characteristics.

Soybean plant growth study conducted using purified protein hydrolysate-based fertilizer made from chrome-tanned leather waste.

Leather processing discharges enormous amount of chrome containing leather solid waste which creates a major disposal problem. Chrome-tanned leather solid waste is a complex of collagen and chromium. The presence of chromium limits protein application in fertilizer industry. The purified protein hydrolysate with zero chromium could be used as a nitrogen source for fertilizer formulation. In this study, an attempt has been made to employ purified protein hydrolysate derived from chrome-tanned leather shavings (CTLS) in formulation of fertilizer. The formulated fertilizer (1­3 t ha(-1)) is employed as nitrogen source in production of soybean. Plant growth study demonstrates that formulated fertilizer dosage 3 t ha(-1) produced similar effects of commercial fertilizer-treated plants. Application of formulated fertilizer yielded higher seed in plant than commercial fertilizer.

A review on management of chrome-tanned leather shavings: a holistic paradigm to combat the environmental issues.

Raw hide/skins come to the tanners as a by-product of meat industry which is converted into value-added leather as product for fashion market. Leather manufacturing is a chemical process of natural biological matrix. It employs a huge quantity of water and inorganic and organic chemicals for processing and thereby discharges solid and liquid wastes into the environment. One of the potential solid wastes generated from leather industry is chrome-tanned leather shavings (CTLSs), and its disposal is increasingly becoming a huge challenge on disposal to tanners due to presence of heavy metal chromium. Hence, finding a sustainable solution to the CTLS disposal problem is a prime challenge for global tanners and researchers. This paper aims to the deeper review of various disposal methods on CTLS such as protein, chromium, and energy recovery processes and its utilization methodologies. Sustainable technologies have been developed to overcome CTLS solid wastes emanating from leather processing operations. Further, this review paper brings a broader classification of developed methodologies for treatment of CTLSs.