Metal bioaccumulation levels in different organs of three edible fish species from the river Ravi, Pakistan

Metals bioaccumulation in five organs of Cirrhinus  mrigala, Labeo  rohita and Catla catla captured from three industrial and sewage polluted downstream sites (Shahdera = B, Sunder = C and Balloki = D) were compared with a non-industrial upstream site (Siphon = A) during high (post monsoon) and low (winter) flow seasons of river Ravi. Mean concentrations of metals were significantly higher in low flow than the high flow season. Pattern of metal accumulation in the studied organs was: Zn > Fe > Mn > Cu > Cr > Pb > Ni > Hg > Cd. Kidneys showed mostly greater metal bioaccumulation than intestines, hearts, eyes and gills. Among fish species, the highest concentrations (µg/g dry weight) of Cr (3.77), Zn (56.22), Mn (8.95), Ni (1.70) and Hg (1.60) and lowest of Pb (2.53) were detected in C. mrigala whereas Cu (7.19), Fe (62.11) and Pb (2.64) appeared higher while Zn (52.69), Mn (7.82) and Ni (1.41) with lowest concentrations in C. catla. In contrast, lower concentrations of Cd (0.15), Cr (3.16), Cu (7.06) and Fe (54.18) were recorded in L. rohita. Accumulation of the metals was significantly different in organs among the different sampling sites. Based on metals accumulation pattern, second downstream site (Sunder) identified as the most polluted site due to untreated industrial and municipal discharges. Measured elevated levels of metals concentrations in fish organs indicated potential health risks for the fish and the food chain

Optimization of sulphuric acid pre-treatment of Acacia saw dust through box-bhenken design for cellulase production by B. Subtilis

Background: Cellulases are enzymes which are capable of degrading lignocellulosic biomass. The current study is centred on optimization of dilute sulphuric acid pre-treatment of Acacia saw dust for maximizing cellulase production (CMCase and FPase). Hydrolysis or saccharification of lignocellulosic biomass is brought about by cellulases and the sugar thus released can be used for further bioethanol production.Methods: Box- Bhenken design (BBD) was employed for optimization of pre-treatment conditions for Acacia saw dust. Three variables i.e. sulphuric acid concentration (0.6%, 0.8% and 1.0% v/v), substrate concentration (5%,10% and15%)  and reaction time (4h,6h and 8h) was optimized. The pre-treated saw dust was used in the study as a substrate for producing cellulase enzyme through submerged fermentation by Bacillus subtilis (K-18).Results: An optimum conditions i.e. (0.8% H2SO4 conc., 15% substrate conc. and 4h of reaction time) yielded highest filter paper activity (1.3617 IU/ml/min) and CMCase activity (0.7783 IU/ml/min). The suggested model was significant as revealed by F-value, coefficient of determination (R2) andP-value.Conclusion: Results concluded that pre-treated substrate (Acacia sawdust) significantly increased cellulase production as compared to untreated substrate that could be utilized for further biofuel production

Original Article Solid state fermentation of fish feed with amylase producing bacteria

Abstract A formulated fish feed was fermented with amylase producing Bacillus cereus (Sn-1 and Sn-3) and Proteus mirabilisis -Sn-2 employing solid state fermentation (SSF) at their corresponding optimized growth conditions. SSF of the fish feed indicated significant increase and decreases in glucose and starch contents within seven days, respectively. Significant elevations also occurred in protein levels as compared to the corresponding values of non fermented control feed. The protein levels increased up to 42.27% by B. cereus-Sn-1 after 24 hours, 63.16% by P. mirabilis-Sn-2 after 168 hours and 47.47% by B. cereus-Sn-3 after 168 hours of incubations. These bacterial isolates caused the nutritional increments with 10% inocula and 70% moisture contents. The C.F.U./g of fermented feeds paralleled, in general, the feed nutritional enrichment. These results are reminiscent to design commercial level solid state fermentation facilities for developing the aquafeed industry in this country

RSM based optimization of nutritional conditions for cellulase mediated Saccharification by Bacillus cereus

Abstract Background Cellulases are enzyme which have potential applications in various industries. Researchers are looking for potential cellulolytic bacterial strains for industrial exploitation. In this investigation, cellulase production of Bacillus cereus was explored while attacking poplar twigs. The bacterium was isolated from the gut of freshwater fish, Labeo rohita and identified by 16S rRNA gene sequencing technology. Various nutritional conditions were screened and optimized through response surface methodology. Initially, Plackett-Burman design was used for screening purpose and optimization was conducted through Box-Bhenken design. Results The maximum cellulase production occurred at 0.5% yeast extract, 0.09% MgSO4, 0.04% peptone, 2% poplar waste biomass, initial medium pH of 9.0, and inoculum size of 2% v/v at 37 °C with agitation speed of 120 rpm for 24 h of submerged fermentation. The proposed model for optimization of cellulase production was found highly significant. The indigenously produced cellulase enzyme was employed for saccharification purpose at 50 °C for various time periods. Maximum total sugars of 31.42 mg/ml were released after 6 h of incubation at 50 °C.The efficiency of this enzyme was compared with commercial cellulase enzyme revealing significant findings. Conclusion These results suggested potential utilization of this strain in biofuel industry

Statistical optimization for deconstruction of poplar substrate by dilute sulfuric acid for bioethanol production

In this study, response surface methodology was used to study the effects of H2SO4, concentrations, substrate loading and residence time on liberation of reducing sugars (RS), total sugars (TS) and total phenolic compounds from poplar leaves and twigs. Box–Behnken design with three variables and three levels showed maximum release of total phenolic compounds (57.39 mg/ml) corresponding to 0.8% H2SO4 concentration, 15% substrate level with residence time of 4 h. Under these conditions, the TS and RS released up to 161.20 and 5.24 mg/ml, respectively. Analysis of the pretreated substrate by Fourier transform infra-red and X-ray diffraction revealed the effectiveness of pretreatment conditions. Second-order polynomial equation using analysis of variance was employed for analyzing the results. The proposed model was found very significant with F-value of 48.39. The R2 and adjusted R2 values also revealed the accuracy of predicted response

Microalgal-bacterial consortium: a cost-effective approach of wastewater treatment in Pakistan

Wastewater treatment using microalgae is an environmental friendly practice, involving various interactions among the micro and macro fauna and flora of treatment plant. The use of algal-bacterial consortia for wastewater treatments has proved more effective in biomass production, nutrient cycling and bioremediation of organic pollutants, heavy metals and many other contaminants. The biodegradation approach of involving consortium might attain self-sustaining level and may prove technically cheaper and advance technology. It will finally help in dealing the dual mission of producing valuable metabolites and pollutants/nutrients removal from wastes/wastewaters. Agricultural wastes/residues generated abundantly in energy deficient countries like Pakistan, having enormous energy potential, are not utilized efficiently and considered as wastes only. The present review focuses on the current research on algal-bacterial consortia and the construction of consortia by keeping in view the environmental conditions of country, suitable for microalgal growth to deal with pollution control and production of animal/fish feed and other valuable metabolites

Biosynthesis and optimization of bacitracin by mutant <em>Bacillus licheniformis </em>using submerged fermentation

251-260The bacitracin is an important antibiotic, which is being used in various biomedical fields. The bacitracin with zinc salt is used in poultry feed to promote growth and to minimize disease incidences. The present study was concerned with the low-cost production of bacitracin using mutant Bacillus licheniformis employing submerged fermentation. Mutant strain was developed from parent culture of B. licheniformis by UV irradiations for different time periods (5 to 40 min). The maximum bacitracin (235 IU/mL) produced by 25 min exposure culture was selected and designated as B. licheniformis PCSIR-410-(5). Culture and fermentation conditions of mutant strain were investigated to improve the yield. Maximum antibiotic (301 IU/mL) production was observed in a soybean meal containing a medium. The highest antibiotic yield was achieved using 24 h old 10% inoculums with 20% dissolved oxygen. While optimizing the conditions it was found that higher levels of antibiotic i.e. 168, 112, 208 and 208 IU/mL were measured at 400 rpm agitation with pH 7.0 at 35oC after 48 h. The result suggested that by using these optimizing conditions for production process by a mutant, B. licheniformis PCSIR-410-(5) and simple techniques for the recovery process, the cost of antibiotic can be decreased to a significant level. The mutated strain could be applied to produce antibiotic at industrial scale to obtain maximum yield

Valorization of Bombax ceiba Waste into Bioethanol Production through Separate Hydrolysis and Fermentation and Simultaneous Saccharification and Fermentation

In this study, Seed pods of B. ceiba were used as a novel, cheap, and sustainable feedstock for second-generation bioethanol production. B. ceiba waste was pretreated with NaOH under different conditions using a Box&ndash;Behnken design (BBD) with three factors and three levels. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to investigate the chemical, structural, and morphological modifications made by pretreatment. NaOH pretreatment followed by steam was more effective as it offered 60% cellulose and 9% lignin at 10% substrate loading, 5% NaOH conc., and 4 h residence time. Samples with maximum cellulose were employed for ethanol production by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) using indigenously produced cellulase as well as commercial cellulase. HPLC analysis revealed the best saccharification (50.9%) at 24 h and the best ethanol yield (54.51 g/L) at 96 h of fermentation in SSF using commercial cellulose by Saccharomyces cerevisiae. SSF offered a better production of bioethanol from seed pods than SHF. The implications of the work support the notion that B. ceiba waste could be utilized for large-scale bioethanol production

Bioethanol Production Optimization from KOH-Pretreated <em>Bombax ceiba</em> Using <em>Saccharomyces cerevisiae</em> through Response Surface Methodology

The present study was based on the production of bioethanol from alkali-pretreated seed pods of Bombax ceiba. Pretreatment is necessary to properly utilize seed pods for bioethanol production via fermentation. This process assures the accessibility of cellulase to the cellulose found in seedpods by removing lignin. Untreated, KOH-pretreated, and KOH-steam-pretreated substrates were characterized for morphological, thermal, and chemical changes by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Hydrolysis of biomass was performed using both commercial and indigenous cellulase. Two different fermentation approaches were used, i.e., separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). Findings of the study show that the maximum saccharification (58.6% after 24 h) and highest ethanol titer (57.34 g/L after 96 h) were observed in the KOH-steam-treated substrate in SSF. This SSF using the KOH-steam-treated substrate was further optimized for physical and nutritional parameters by one factor at a time (OFAT) and central composite design (CCD). The optimum fermentation parameters for maximum ethanol production (72.0 g/L) were 0.25 g/L yeast extract, 0.1 g/L K2HPO4, 0.25 g/L (NH4)2SO4, 0.09 g/L MgSO4, 8% substrate, 40 IU/g commercial cellulase, 1% Saccharomyces cerevisiae inoculum, and pH 5

Alantolactone: A Potential Multitarget Drug candidate for Prevention of SARS-CoV-2 Cell Entry

The novel strain of coronavirus, SARS-CoV-2, has spread adverse effects on human health with high mortality rates worldwide. SARS-CoV-2 is a severe respiratory disease expressed through positive single stranded RNA enveloped virus. SARS-CoV-2 had affected globally and is influencing the economy as well. The rapidly spreading coronavirus infection has discombobulated the researchers in perpetuate search for different or effective therapeutic drugs.  Most of the connatural products are proposed to have significant clinical outcomes but their pathways of action are not clear. This molecular docking study presents alantolactone, a bio-active member of sesquiterpene family as a successful inhibitor of SARS-Cov-2 and human receptor proteins. Alantolactone shows high binding affinity with the SARS-CoV-2 target proteins such as spike glycoprotein (S-protein), nucleocapsid protein (N-protein), main protease (MPro), and papain-like protease (PLPro) with a binding affinity of -7.3 kcal/mol, -7.9 kcal/mol, -6.8 kcal/mol, and -7.1 kcal/mol, respectively as well as human receptor  proteins associated with the recognition, binding and biogenesis of SARS-CoV-2 such as angiotensin-converting enzyme 2 (ACE-2), receptor binding domain (S1-RBD) and ACE2 interphase, furin, adaptor-associated protein kinase 1 (AAK1), cyclin G-associated kinase (GAK), and both closed and open configurations of the two-pore channel (TPC2) with binding energies of -6.7 kcal/mol, - 6.9 kcal/mol, -8.1 kcal/mol, -7.3 kcal/mol, and -7.9 kcal/mol, respectively. Molecular docking and ADMET properties and toxicity predictions suggest that alantolactone could effectively binds with various viral target protein and human target proteins and could be developed into a novel SARS-coV-2 inhibitor