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).

Baseline Characteristics Associated with Good Collateral Status Using Hypoperfusion Index as an Outcome.

Up to 30% of ischemic stroke cases are due to large vessel occlusion (LVO), causing significant morbidity. Studies have shown that the collateral circulation of patients with acute ischemic stroke (AIS) secondary to LVO can predict their clinical and radiological outcomes. The aim of this study is to identify baseline patient characteristics that can help predict the collateral status of these patients for improved triage. In this IRB approved retrospective study, consecutive patients presenting with AIS secondary to anterior circulation LVO were identified between September 2019 and August 2021. The baseline patient characteristics, laboratory values, imaging features and outcomes were collected using a manual chart review. From the 181 consecutive patients initially reviewed, 54 were confirmed with a clinical diagnosis of AIS and anterior circulation LVO. In patients with poor collateral status, the body mass index (BMI) was found to be significantly lower compared to those with good collateral status (26.4 ± 5.6 vs. 31.7 ± 12.3; p = 0.045). BMI of >35 kg/m2 was found to predict the presence of good collateral status. Age was found to be significantly higher (70.5 ± 9.6 vs. 58.9 ± 15.6; p = 0.034) in patients with poor collateral status and M1 strokes associated with older age and BMI.