Efficient Bioethanol Production from Lignocellulosic Biomass Using Diverse Microbial Strains

Forestry residues (FR) and medicinal-aromatic plant waste (MAPW) are considered potential resources for energy recovery. In this context, we explore the bioethanol production potential of three microbial strains Aspergillus niger, Zymomonas mobilis, and Trichoderma longibrachiatum using this lignocellulosic hydrolysate as a substrate. The blend of FR and MAPW was pretreated by different methods like acid sulfuric (AS), steam explosion (SE), and enzymatic (E). The ethanol yield was measured by gas chromatography (GC). Zymomonas mobilis demonstrated the highest ethanol yield of 5.95% on untreated substrate. Conversely, Aspergillus niger exhibited peak performance with an ethanol yield of 10.78% following AS, SE and E combined pretreatment. Trichoderma longibrachiatum, yielded ethanol ranging from 1.27% to 2.47%. Furthermore, the use of immobilized d’ Aspergillus niger strains revealed a small decrease in ethanol yield from 11.34% in the first cycle to only 5.02% in the sixth cycle. In conclusion, Aspergillus niger emerges as a promising candidate due to its dual functionality in pretreatment and ethanol fermentation, offering pathways for advancing sustainable biofuel technologies.