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The neoagarooligosaccharides have received growing attention owing to their physiological activities. The aim of this study was the isolation of agarase-producing bacteria for production of agar hydrolysates with special emphasis on their anti-oxidant potential. An agarolytic strain NI125 was isolated from Nelson's Island, Alexandria, Egypt. Based on 16S rRNA analysis and extensive phenotypic characterization, it was identified as Aquimarina agarilytica. Maximum enzyme production was achieved after 24 h incubation at 20°C, and tryptone was recorded to be the best nitrogen source for agarase production. Extracellular agarase was partially purified by ammonium sulfate precipitation. The substrate specificity assay using p-nitrophenyl-α/β-D-galactopyranoside revealed the cleavage of the β-linkage rather than the α-linkage. Neoagarooligosaccharides produced by the partially purified β-agarase expressed promising anti-oxidant properties, with 23% free radical scavenging potential. Notable enhancement of the anti-oxidant potency of the oligosaccharides was achieved (up to 87% scavenging ability) by sulfation of the agar prior to hydrolysis for 12 h with β-agarase. Results obtained suggest the potential application of the produced neoagarooligosaccharides anti-oxidants as promising additives in food and feed products.

Salinity is one of the most crucial stressors that restrain crop productivity. Endophytes with 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity possess the potential to ameliorate salt stress in plants by degrading the precursor molecule of ethylene, ACC, whose concentration is elevated in salt-stressed plants. The present investigation reports the efficiency of salt-tolerant endophyte Bacillus aryabhattai EWR29 exhibiting ACC deaminase activity as bioinoculant to improve the growth of the wheat plant under salinity stress conditions. The strain EWR29 manifested multifarious plant growth-promoting traits including, phosphate solubilization, and production of indole acetic acid (IAA), siderophore, HCN, and exopolysaccharides (EPS). Besides, it endures salinity (12%) and, drought stresses (−0.49 MPa) and showed a strong biofilm-formation potential. Moreover, acdS gene coding for ACC deaminase was sequenced and characterized at the molecular level. Inoculation of wheat plants with B. aryabhattai EWR29 alleviated the negative effects of salinity stress and promoted significant increases in growth criteria compared with un-inoculated plants grown at the same salinity levels. The bioinoculant induced up-regulation of the antioxidant enzymes peroxidase (POD) and superoxide dismutase (SOD), and decreased proline content in treated plants indicating the mitigation of salt effect. The results indicated the potential used of B. aryabhattai EWR29 as bioinoculant to enhance the growth of wheat plants cultivated in salt-affected agriculture fields and alleviate salt stress

β-galactosidase (E.C.3.2.1.23) has been widely used in dairy and pharmaceutical industries. In this study, Bacillus megaterium NM56 showing maximum production of β-galactosidase was isolated from raw milk. Effects of various culture conditions, namely, incubation period, temperature, pH, carbon source and nitrogen source were investigated. Results revealed that the highest level of β-galactosidase was produced after 48 h of incubation. Optimal temperature and pH for production was observed at 40°C and 7.5, respectively. Galactose, lactose, tryptone and yeast extract were the best carbon and nitrogen sources for enzyme production. Permeabilization efficiency of different solvents was assessed and results indicated that iso-propanol was the most potent permeabilizing agent