•Hydrogen producing strains isolated from food based industrial wastewater.•Four effective microbial isolates - FH1, FB1, FA2 and SB2 were used.•K. pneumoniae-FA2 produced maximum H2 production of ...880.93 ± 44.0 mL/L.•K. pneumoniae-FA2 produced H2 yield of 3.79 ± 0.04 mol H2/mol glucose.•Improved bioelectricity generation by K. pneumoniae-FA2 anodic biofilm in MFC.
In the present study, isolation and identification of hydrogen producing strains from sugar and food industry wastewater were reported. From 48 isolates in both the wastewater, initial batch studies led to the use of four effective strains, which were identified using 16S rRNA gene sequencing as Bacillus thuringiensis-FH1, Comamonas testosteroni-FB1, Klebsiella pneumoniae-FA2 and Bacillus cereus-SB2, respectively. Further optimization studies were done at various pH values (5–8) and wastewater concentrations (10–100%). In the optimized batch experimentation, K. pneumoniae-FA2 excelled with the maximum cumulative hydrogen production of 880.93 ± 44.0 mL/L. A 3 L bioreactor was employed for effective hydrogen production, which conferred that K. pneumoniae-FA2, surpassed the other three with the maximum hydrogen yield of 3.79 ± 0.04 mol H2/mol glucose. Bioelectricity production by K. pneumoniae-FA2 was also investigated in the microbial fuel cell at the optimized conditions to demonstrate its versatility in energy applications.
Fossil fuel energy depletion and removal of environmental wastes are big problem in many countries. Some of the wastes contain a considerable amount of protein and carbon compounds; little ...concentration is given to utilizing or recycling these wastes in a technological way for production of renewable energy. Feathers are generated in large amounts as waste at commercial poultry processing plant, reaching millions of tons per year worldwide. Feathers are rich in keratin protein. In this work, keratin was degraded and the degraded effluent was evaluated for biohydrogen production by anaerobic (dark fermentation) process. The keratin degrading microorganisms were isolated from the soil sample where the feather wastes were disposed using minimal media with prepared keratin powder. The isolates were named as KHAD1, KHAD2 and KHAD3. The isolates were identified as Serratia marcescens KHAD1 (MH422128), Bacillus subtilis KHAD2 (MH422129) and Pseudomonas aeruginosa KHAD3 (MH422009) based on their 16S rRNA sequencing. The isolates were screened for biodegradability of keratin protein and higher biodegrading potential microorganism such as Pseudomonas aeruginosa KHAD3. The optimization studies for biohydrogen production using isolates in keratin degraded effluent at various pH (1, 2, 4, 6, 8, 10 & 11). The maximum biohydrogen production was obtained at pH 11 (210 ml/L) by Pseudomonas aeruginosa KHAD3. Keywords: Biohydrogen, Keratin biodegradation, poultry waste, chicken feather, Dark fermentation.
The bio hydrogen (H2 ) production by anaerobic digestion of industrial waste is beneficial one due to the availability of proteins and carbohydrates as potential substrate for biological H2 ...production. An anaerobic fermentative route is a promising method of biohydrogenation. The microbial isolates from various industrial wastes (dairy, sugar and food) were assessed for their potential bio H2 production. The selected individual isolates (F1 - Bacillus subtilis and A3 -Bacillus subtilis) and their cocultures were used for the optimization of bio H2 production utilizing various concentration of biscuit industry waste as substrate at various pH conditions. The mixed consortium which displayed the higher bio H2 production was selected for the detailed analysis of the 3L fermentation studies using 90% Organic Loading Rate (OLR) substrate at pH 6.5. Significantly higher Hydrogen Yield (HY) of 0.87 mol H2 /mol glucose on 16th day of incubation was observed.
The present study aims to enhance the efficiency of anaerobic sludge microorganisms to produce hydrogen (H.sub.2) through various pre-treatment methods. The various pre-treatment methods such as ...base, acid, chloroform, heat shock, freezing and thawing have enabled to isolate acidogenic bacteria with higher bio H.sub.2 producing activity in an anoxic environment. From these various treatments, bacteria were isolated and screened for bio H.sub.2 capabilities. Among the one bacterial strain, AH4 strain showed maximum cumulative H.sub.2 production and Hydrogen Yield (HY) using 100% diary anaerobic sludge. AH4 strain was identified as Acinetobacter junii using 16S rRNA gene sequence and used for further experimental analysis. Biohydrogen productions of Acinetobacter junii were measured at different experimental setup such as various pH levels (5.0, 5.5, 6.0, 6.5, 7.0, 7.5 and 8.0) and different substrate concentration (10-100%) of dairy anaerobic sludge substrate. At pH 7.5 and 60% substrate concentration, the strain AH4 Acinetobacter junii displayed the maximum cumulative H.sub.2 production of 945.7 ml/L and H.sub.2 yield 1.35 mol H.sub.2/ mol glucose. Based on our results, we concluded that Acinetobacter junii can be used as a promising bio agent for hydrogen production on a large scale using dairy anaerobic sludge as substrate.Key words: Bio hydrogen, Dairy industry anaerobic sludge, Pretreatment, Optimization, Batch experiment.
Hydrogen (H2) is one of the most promising renewable energy sources, anaerobic bacterial H2 fermentation is considered as one of the most environmentally sustainable alternatives to meet the ...potential fossil fuel demand. Bio-H2 is the cleanest and most effective source of energy provided by the dark fermentation utilizing organic substrates and different wastewaters. In this study, the bio-H2 production was achieved by using the bacteria Acinetobacter junii-AH4. Further, optimization was carried out at different pH (5.0–8.0) in the presence of wastewaters as substrates (Rice mill wastewater (RMWW), Food wastewater (FWW) and Sugar wastewater (SWW). In this way, the optimized experiments excelled with the maximum cumulative H2 production of 566.44 ± 3.5 mL/L (100% FWW at pH 7.5) in the presence of Acinetobacter junii-AH4. To achieve this, a bioreactor (3 L) was employed for the effective production of H2 and Acinetobacter junii-AH4 has shown the highest cumulative H2 of 613.2 ± 3.0 mL/L, HPR of 8.5 ± 0.4 mL/L/h, HY of 1.8 ± 0.09 mol H2/mol glucose. Altogether, the present study showed a COD removal efficiency of 79.9 ± 3.5% by utilizing 100% food wastewater at pH 7.5. The modeled data established a batch fermentation system for sustainable H2 production. This study has aided to achieve an ecofriendly approach using specific wastewaters for the production of bio-H2.
•Acinetobacter junii-AH4 can be used for biohydrogen producing potential bacteria.•Two factors affecting biohydrogen production of Acinetobacter junii-AH4 were optimized.•In this study 3L bioreactor was employed for effective hydrogen production.•Maximum hydrogen yield of 1.8 ± 0.09 mol H2/mol glucose by utilizing 100% FWW at pH 7.5.
The present study is focused on bio hydrogen (H2) and bioplastic (i.e., poly-β-hydroxybutyrate; PHB) productions utilizing various wastes under dark fermentation, photo fermentation and subsequent ...dark-photo fermentation. Potential bio H2 and PHB producing microbes were enriched and isolated. The effects of substrate (rice husk hydrolysate, rice straw hydrolysate, dairy industry wastewater, and rice mill wastewater) concentration (10–100%) and pH (5.5–8.0) were examined in the batch mode under the dark and photo fermentation conditions. Using 100% rice straw hydrolysate at pH 7, the maximum bio H2 (1.53 ± 0.04 mol H2/mol glucose) and PHB (9.8 ± 0.14 g/L) were produced under dark fermentation condition by Bacillus cereus. In the subsequent dark-photo fermentation, the highest amounts of bio H2 and PHB were recorded utilizing 100% rice straw hydrolysate (1.82 ± 0.01 mol H2/mol glucose and 19.15 ± 0.25 g/L PHB) at a pH of 7.0 using Bacillus cereus (KR809374) and Rhodopseudomonas rutila. The subsequent dark-photo fermentative bio H2 and PHB productions obtained using renewable biomass (i.e., rice husk hydrolysate and rice straw hydrolysate) can be considered with respect to the sustainable management of global energy sources and environmental issues.
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•Bio H2, PHB production by DF, PF was optimized utilizing RHH, DWW, RWW and RSH.•Subsequent DF-PF fermentation offers better yield (H2 and PHB) than DF.•Higher amount of bio H2 and PHB production were recorded at 100% RSH.•PHB and H2 production by DF-PF fermentation led to reductiofn of production cost.
TiO
-ZnO heterogeneous catalytic system provides a good replacement of a homogeneous catalytic reaction due to its easier recovery. In this study, biodiesel was produced from Ulva lactuca seaweeds ...using TiO
-ZnO nanocomposite catalysts with particle size of ~12 nm. The size controlled TiO
-ZnO nanocomposite was characterized by powder XRD analysis and TEM. The result of that TiO
-ZnO catalyst is a promising catalyst for the production of biodiesel under mild reaction conditions and high yield of hydroxydecanoic acid conversion of 82.8%. The various conditions optimized for the higher conversion to FAME (15.8 ml of FAME) were 4 wt% catalysts at 4 h under 60 °C and further there is no increase of conversion to FAME above 60 °C-80 °C. The total product yield was calculated as 82.8% of conversion to FAME. The evaluated biodiesel was found to be up to the mark of ASTM standards. The silver nanoparticles (AgNPs) were synthesized by using leftover biomass of algae obtaining after lipid extraction of U.lactuca. AgNPs particle size was achieved as ~12 nm and was confirmed by UV-Visible spectroscopy, XRD and TEM analysis. Antibacterial activities of the synthesized AgNPs were analyzed and compared. The antibacterial activity was excellent against bacterial pathogens and treatment against P. vulgaris shows the maximum zone of inhibition (13.8 mm). The present work identified that the unutilized bioresource such as U.lactuca can be effectively utilized for biodiesel production so as to replace fossil fuel usage.
TiO2-ZnO heterogeneous catalytic system provides a good replacement of a homogeneous catalytic reaction due to its easier recovery. In this study, biodiesel was produced from Ulva lactuca seaweeds ...using TiO2–ZnO nanocomposite catalysts with particle size of ~12 nm. The size controlled TiO2–ZnO nanocomposite was characterized by powder XRD analysis and TEM. The result of that TiO2–ZnO catalyst is a promising catalyst for the production of biodiesel under mild reaction conditions and high yield of hydroxydecanoic acid conversion of 82.8%. The various conditions optimized for the higher conversion to FAME (15.8 ml of FAME) were 4 wt% catalysts at 4 h under 60 °C and further there is no increase of conversion to FAME above 60 °C–80 °C. The total product yield was calculated as 82.8% of conversion to FAME. The evaluated biodiesel was found to be up to the mark of ASTM standards. The silver nanoparticles (AgNPs) were synthesized by using leftover biomass of algae obtaining after lipid extraction of U.lactuca. AgNPs particle size was achieved as ~12 nm and was confirmed by UV–Visible spectroscopy, XRD and TEM analysis. Antibacterial activities of the synthesized AgNPs were analyzed and compared. The antibacterial activity was excellent against bacterial pathogens and treatment against P. vulgaris shows the maximum zone of inhibition (13.8 mm). The present work identified that the unutilized bioresource such as U.lactuca can be effectively utilized for biodiesel production so as to replace fossil fuel usage.
•Utilization of TiO2–ZnO heterogeneous catalyst FAME production from Ulva lactucaseaweed.•TiO2–ZnO catalyst has shown good catalytic activity and high yield FAME conversion of 82.8%.•By the means of waste utilization leftover biomass after lipid extraction applied for AgNPs synthesis.•Spherical, ~24 nm sized AgNPs shows higher antibacterial activity.
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