Abstract
Vitamins are vital micronutrients needed for the body's regular functioning and progression; they are precursors of intracellular co-enzymes. Plants and microbes synthesise vitamins naturally, but human beings and animals are unable to synthesise most vitamins, thus the vitamins must be obtained through diets. Vitamin deficiency can result in a variety of disorders, including pellagra and nerve damage. Vitamins are produced using a variety of ways, including chemical synthesis, bioconversion processing, and microbial fermentation. Microbial fermentation for vitamin production is gaining popularity since it is less expensive, produces less waste, more sustainable, and ecologically benign. Endophytes are microorganisms (bacteria, actinomycetes, and fungi) that live in a symbiotic relationship with plants. Endophytes secrete secondary metabolites, including vitamins, that have a variety of biotechnological applications. Following the findings that most bacterial species produce vitamins, the primary goal of this study was to assess the production, and antioxidant activity of B-group vitamins (B1, B3, B6 and B9) by endophytic bacteria; Bacillus paranthracis strain MHSD3 and Pantoea ananatis strain MHSD2 isolated from Pellaea calomelanos. Moreover, to identify the vitamins using high performance liquid chromatography mass spectrometer (HPLC-MS) and elucidate metabolic pathways that the extracted B-group vitamins are involved in either the human or bacteria metabolism. Both bacterial endophytes synthesised and produced the vitamins, with strain MHSD3 producing the most vitamin B9 at 20.107 g/mL, whereas strain MHSD2 produced the most vitamin B1 at 15.557 g/mL. Endophytic strains produced modest levels of vitamin B6, with MHSD3 secreting 11.447 g/mL and MHSD2 secreting 5.589 g/mL. The antioxidant activity results showed that strain MHSD3 had the highest DPPH and ABTS scavenging activity at 75.5% and 60.7% for vitamin B9, while strain MHSD2 had the highest DPPH and ABTS scavenging activity at 69.3% and 67.1% for vitamin B9 and B1, respectively. Using in silico analysis, many metabolic pathways in humans and bacteria were identified in which the extracted B-group vitamins; B1, B3, B6, and B9 are involved.
Keywords: Antioxidant activity, Bacillus paranthracis, Bacterial endophytes, In silico analysis, Microbial fermentation, Pellaea calomelanos, Pantoea ananatis, Vitamins.