Bioenergy production from chicken feather waste by anaerobic digestion and bioelectrochemical systems.

BACKGROUND: Poultry feather waste has a potential for bioenergy production because of its high protein content. This research explored the use of chicken feather hydrolysate for methane and hydrogen production via anaerobic digestion and bioelectrochemical systems, respectively. Solid state fermentation of chicken waste was conducted using a recombinant strain of Bacillus subtilis DB100 (p5.2). RESULTS: In the anaerobic digestion, feather hydrolysate produced maximally 0.67 Nm3 CH4/kg feathers and 0.85 mmol H2/day.L concomitant to COD removal of 86% and 93%, respectively. The bioelectrochemical systems used were microbial fuel and electrolysis cells. In the first using a microbial fuel cell, feather hydrolysate produced electricity with a maximum cell potential of 375 mV and a current of 0.52 mA. In the microbial electrolysis cell, the hydrolysate enhanced the hydrogen production rate to 7.5 mmol/day.L, with a current density of 11.5 A/m2 and a power density of 9.26 W/m2. CONCLUSIONS: The data indicated that the sustainable utilization of keratin hydrolysate to produce electricity and biohydrogen via bioelectrical chemical systems is feasible. Keratin hydrolysate can produce electricity and biofuels through an integrated aerobic-anaerobic fermentation system.

Valorization of chicken feather waste using recombinant bacillus subtilis cells by solid-state fermentation for soluble proteins and serine alkaline protease production.

Feather waste, a by-product of the poultry industry, is rich in proteins, peptides, and amino acids. Improper disposal of feathers can cause environmental pollution. Solid-state fermentation (SSF) is a viable alternative to submerged fermentation due to its simplicity, productivity, and lower cost. The study goal is a biorefinery of chicken feather waste supplemented with wheat bran using a recombinant Bacillus subtilis strain to produce soluble proteins and a serine alkaline protease. Plackett-Burman Design and Central Composite Design were utilized in a statistical-mathematical model to optimize the process. Multi-factorial design optimization resulted in 80 % substrate degradation efficiency, an alkaline protease with dual activities (1423 proteolytic units and 190 keratinolytic units), 214 mg soluble proteins/g substrate, and 87 % model validation. Scaling up the SSF process to 50 g of substrate significantly enhanced the end products of feather biodegradation to 1616 proteolytic units, 2844 keratinolytic units, and 127 mg soluble proteins/g substrate. AIM AND SCOPE OF THE MANUSCRIPT: The aim of the present study is to utilize chicken feather waste (alone or supplemented with other materials) through recombinant Bacillus subtilis cells using solid state fermentation (SSF) at a laboratory scale. The plan study provides a promising waste management in the environmental field concerning biodegradation of such recalcitrant keratinous wastes supplemented with agricultural residues via recombinant microorganism. On semi-pilot scale, high production and quality of soluble protein, protease, and keratinase activity were produced according to the statistically optimised first stage fermentation in the laboratory scale. The bioconversion process took place as a major goal to obtain valuable products, with low utilities and energy requirements. Therefore, this will consider as an economically feasible and environmentally friendly alternative. Moreover, this study is considered as first step fermentation for feather waste to pave the road for directing it to a second step fermentation for biogas production and bioenergy generation through bio-electrochemical systems (Manuscript under publication).

Exogenously Applied Proline Enhances Morph-Physiological Responses and Yield of Drought-Stressed Maize Plants Grown Under Different Irrigation Systems.

The exogenous application of osmoprotectants [e.g., proline (Pro)] is an important approach for alleviating the adverse effects of abiotic stresses on plants. Field trials were conducted during the summers of 2017 and 2018 to determine the effects of deficit irrigation and exogenous application of Pro on the productivity, morph-physiological responses, and yield of maize grown under two irrigation systems [surface irrigation (SI) and drip irrigation (DI)]. Three deficit irrigation levels (I100, I85, and I70, representing 100, 85, and 70% of crop evapotranspiration, respectively) and two concentrations of Pro (Pro1 = 2 mM and Pro2 = 4 mM) were used in this study. The plants exposed to drought stress showed a significant reduction in plant height, dry matter, leaf area, chlorophyll content [soil plant analysis development (SPAD)], quantum efficiency of photosystem II [Fv/Fm, Fv/F0, and performance index (PI)], water status [membrane stability index (MSI) and relative water content (RWC)], and grain yield. The DI system increased crop growth and yield and reduced the irrigation water input by 30% compared with the SI system. The growth, water status, and yield of plants significantly decreased with an increase in the water stress levels under the SI system. Under the irrigation systems tested in this study, Pro1 and Pro2 increased plant height by 16 and 18%, RWC by 7 and 10%, MSI by 6 and 12%, PI by 6 and 19%, chlorophyll fluorescence by 7 and 11%, relative chlorophyll content by 9 and 14%, and grain yield by 10 and 14%, respectively, compared with Pro0 control treatment (no Pro). The interaction of Pro2 at I100 irrigation level in DI resulted in the highest grain yield (8.42 t ha-1). However, under the DI or SI system, exogenously applied Pro2 at I85 irrigation level may be effective in achieving higher water productivity and yield without exerting any harmful effects on the growth or yield of maize under limited water conditions. Our results demonstrated the importance of the application of Pro as a tolerance inducer of drought stress in maize.

Protective effect of grape seed extract against chronic physical stress-induced zona fasciculata injury in male rats: Functional, immunohistochemical and electron microscopic study.

In the present study, we investigated the antioxidant effect of grape seed extract (GSE) against chronic immobilization stress-induced zona fasciculata injury in Wistar male rats. Thirty male rats were divided into three groups: Non-stress group: rats were not subjected to stress protocol and received distilled water orally for 30 days. Stress group: rats received distilled water orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), distilled water was continued along with the constant stress experiment. GSE-stress group: rats treated with oral GSE (300 mg/kg), administered orally for 15 consecutive days before the induction of chronic immobilization stress experiment (repeated stress for 15 consecutive days), GSE was continued along with the stress exposure. Chronic stress was induced by placing each animal in a restrainer for 2 h daily for 15 consecutive days in both Stress and GSE-stress groups. The serum corticosterone and adrenal cortex malondialdehyde (MDA) levels were measured as indices of stress. Immunohistochemistry of the inducible nitric oxide synthase (iNOS) as a nitrosative stress marker beside the adrenal cortex's ultrastructure, particularly zona fasciculata, was assessed. Chronic restraint stress significantly elevated the serum corticosterone and adrenal cortex MDA levels, while oral administration of GSE reduced the serum corticosterone level, adrenal cortex MDA levels, and iNOS immunoreactivity in zona fasciculata. Besides, adrenocortical ultrastructure significantly improved. These results suggested that GSE enhanced the antioxidant defense against reactive oxygen species produced under chronic stress conditions, protecting the adrenal cortex. RESEARCH HIGHLIGHTS: This research highlighted the significant protective effects of grape seed extract administration on the histological findings, both in light and electron microscopic studies, as well as the biochemical and functional parameters in cases of stress-induced adrenal cortex injury in rats.

Effect of nebivolol on altered skeletal and cardiac muscles induced by dyslipidemia in rats: impact on oxidative and inflammatory machineries.

AIM: High cholesterol diet is greatly linked to deleterious health consequences. In this work we tried to explore direct effects of high cholesterol diet on striated (skeletal and cardiac) muscle tissues and the mechanisms by which nebivolol could improve such harmful effects. METHODS: The study included 24 healthy adult male albino rats weighing 200-220 grams that were assigned into four groups: control group, control drug group, high cholesterol diet fed groups; one untreated the other was treated with nebivolol. RESULTS: In the cholesterol fed group, we found decreased blood HDL and NO with elevated total cholesterol, triglycerides, myoglobin, CK, LDH, ALP, in addition to elevated muscle tissue levels of HIF-1, NF-kB, MDA, and decreased expression of both eNOS, reduced GSH. Wire hanging test time was shorter in the high cholesterol group than control group rats, which was confirmed histologically by increased striated muscle fibre thickness and cytochrome area %. Nebivolol treatment ameliorated the effects of high cholesterol diet. CONCLUSION: High cholesterol diet caused myopathic changes in rat striated muscle tissues mostly due to oxidative stress associated with enhanced NF-kB and HIF-1 expression. Nebivolol appears beneficial in the management of hypercholesterolaemia-induced striated muscle injury.

Interrelation of liver vascularity to non-alcoholic fatty liver through a comparative study of the vasodilator effect of carvedilol or nicorandil in rats.

AIM: An experimental study of the effect of two vasodilators, carvedilol (B blocker with alpha-antagonist) and nicorandil (NO donor) on nonalcoholic fatty liver (NAFLD) induced by hypercholesterolemia and fatty diet in rats through studying the possible anti-inflammatory and antioxidant mechanisms. MAIN METHODS: The rats were divided into 4 groups (6 rats each): The first (negative control group). The second, third and fourth groups were fed with cholesterol and fat- enriched diet for one month that stopped and continued on the standard diet for another month without treatment in the second group but treated with carvedilol and nicorandil in the third and fourth group respectively. KEY FINDINGS: They revealed that both improved NAFLD especially nicorandil treated proved by the reduction of liver enzymes (AST, ALT), the fatty infiltration determined histologically and biochemically (decrease liver triglycerides). This may be due to either being antioxidants (reduced malondialdehyde and elevated reduced glutathione) or anti-inflammatory (decreased of TNF-α) together with the reduction of insulin resistance and adiponectin elevation or gene expression (increased liver NF-κB and decreased eNOS expression) and finally maybe by their obvious effect on improvements of lipid parameters. SIGNIFICANCE: Carvedilol and nicorandil improved NAFLD through the interrelationship between inflammatory cytokines, antioxidants and insulin resistance.

Liver glycogenoses: are they a possible cause of polyneuropathy? A cross-sectional study.

We encountered two children suffering from liver glycogenoses (GSD) over a period of 5 years (1992-1997) who presented with a demyelinating peripheral neuropathy diagnosed by electromyography (EMG) and nerve conduction studies (NCV). The aim of the study was to evaluate the involvement of muscle and motor nerve in children suffering from liver glycogenoses. In a cross-sectional study, 22 children suffering from liver GSD (with no current neurological symptoms) and 20 age- and sex- matched clinically free children (control group) underwent creatine phospho-kinase (CPK), EMG, and NCV studies. Abnormal EMG and/or NCV studies were found in 11 children. Six (27.27 per cent) were found to have axonopathy, three (13.63 per cent) demyelinating polyneuropathy, and two (9.1 per cent) had mixed axonal and demyelinating neuropathy. Two children with axonopathy had GSD type VI, another had GSD type IV, and three had GSD of undiagnosed type. Three of those having a demyelinating polyneuropathy had GSD type III, another had GSD type IV, and the last had GSD of undiagnosed type. None were found to have a cardiomyopathy or a myopathy on EMG. This is the first report of neuropathy associated with GSD types III, IV, and VI in children. It might be discovered by EMG and/or NCV studies in a clinically, neurologically normal child suffering from GSD, or present as an acute polyneuropathy.