Potential of Kluveromyces marxianus NCIM 3465 and Rhizopus oryzae NCIM 1387 for bio-ethanol production from agro industrial and spent wastes of Camelia sinensis

Tea production and processing enterprises in several industrialized and developing nations are generating a huge byproduct and solid waste, thereby posing a distress and pervasive issues. Consequently, the global research community has started focusing on the exploration of sustainable ways that would repurpose tea waste (TW) in numerous utilizations. This research focuses on the beneficial usage of TW biomass in bioethanol production along with the sustainable reutilization of tea industry waste in a sustainable manner. Bioethanol is a clean and renewable energy resource that has gained escalated concentration as a prospective substitute for non-renewable and conventional petroleum-based fuels. In this research field waste, industrial waste and spent tea waste of Camelia sinensis were explored for their potential to produce bioethanol by Kluveromyces marxianus NCIM 3465 and Rhizopus oryzae NCIM 1387. It was found that both Kluveromyces marxianus NCIM 3465 and Rhizopus oryzae NCIM 1387 produced maximum ethanol (437.69 ± 1.22 mg ml–1 and 500.87 ± 2.42 mg ml–1 respectively) from 10 per cent (wt/v) HNO3 pretreated field waste. Kluveromyces marxianus NCIM 3465 produced maximum amount of ethanol 341.45 ± 2.02 mg ml–1 whereas Rhizopus oryzae NCIM 1387 (F) produced maximum amount of ethanol 388.14 ± 2.82 mg ml–1, respectively in 6 and 10 per cent (wt/v) HNO3 pretreated industrial waste. Maximum amount of ethanol was generated from spent tea waste by Kluveromyces marxianus NCIM 3465 and Rhizopus oryzae NCIM 1387 when this waste was pretreated with 6 per cent (wt/v) HNO3 viz. 515.82 ± 3.80 and 499.86 ± 2.72 mg ml–1, respectively