Biorefinery-fermentation of agro-wastes by Haloferax lucentensis GUBF-2 MG076878 to Haloextremozymes for use as biofertilizer and biosynthesizer of AgNPs

Abstract

Purpose: The green biorefnery approach is an alternative to the chemical method of production of enzyme-rich hydrolysate from waste biomass. Specifcally, feather and coconut oil cake (COC) hydrolysate manifests the generation of bioproducts like dietary fbers, biofertilizers, bioplastics, esters, nanoparticles, etc. Methods: We scaled up the production of haloextremozyme-rich hydrolysates using Haloferax lucentensis GUBF-2 MG076878 in an economical bioreactor for valuation as biofertilizer for rice growth and biosynthesis of silver nanoparticles (AgNPs), showing antimicrobial activity. Results The strain solubilizes 10 percent feather and COC with 78.75 plus or minus 0.717 percent and 88.35 plus or minus 0.654 percent degradation after 20 days, respectively. Moreover, tangential fltration aided co-concentration of both protease and lipase from feather/COC hydrolysate to greater than 70 percent yield. SEM of feather/COC hydrolysate depicted particle size ranging 100-10000 nm. FTIR evidenced the functional groups of greater than C=O, -CH, -NH, -CH sub(3), OH, and COO-. Priming seeds of rice with feather hydrolysate resulted in 100 percent germination energy and higher vigor index (1214), alongside increased shoot length (43.2 plus or minus 0.58) under saline conditions. Biosynthesized AgNPs showed absorption maxima at 440 nm and vibrations of -CH, -OH, -NH, greater than C=C, and greater than C=O functionality in FTIR. AFM depicted the semi-oval morphology of AgNPs with a maximum height of 22 nm. Also, the presence of silver was confrmed by SEM-EDAX. AgNPs exhibited antimicrobial activity against human pathogens as; C. albicans greater than S. aureus greater than S. pyogenes greater than E. coli ATCC 8439 greater than P.vulgaris, and S.typhi. Conclusion: Conclusively, the production of haloextremozyme-rich feather and COC hydrolysate via the biorefnery approach employing Haloferax lucentensis GUBF-2; is lucrative, considering waste valorization and biosynthesis of bioproducts in biotechnological applications.