Fungal Biocontrol Agents as a New Source for Bioethanol Production

Abstract

Fossil fuels and chemical pesticides could probably be blamed for future human downfall. Therefore, the global dependence on fossil fuels must be reduced immediately due to climate change, environmental issues, and health complications. The latter two negative effects could also be rendered by chemical pesticides. Among renewable energy alternatives, liquid biofuels have higher compatibility with the current fuel infrastructures and engines (i.e., transportation, storage, and engine systems), and hence, are very promising for transportation sector. Bioethanol, a liquid biofuel, is an ideal gasoline extender and is widely used in many countries in blended form with gasoline at specific ratios to improve fuel characteristics and engine performance. Although the bioethanol production industry has long been operational, finding suitable and sustainable feedstock is still an active field of study. The consumption of food/feed commodities such as sugarcane and corn (i.e., the first-generation bioethanol) has raised food vs. fuel debate. Alternatively, scientists have concentrated on the second-generation bioethanol, which consumes wastes such as lignocelluloses. However, huge amounts of hydrolytic enzymes, particularly cellulases, are required that contribute to high bioethanol production cost. Fungal biocontrol agents are superb producers of these enzymes, while at the same time they could be used as effective biological pesticides for sustainable agriculture. In this chapter, a novel viewpoint is put forward for sustainable direct production of bioethanol from lignocellulose by fungi, which could easily be separated at the end of the process and be exploited as biological control agents. For this purpose, several promising species within Fusarium, Paecilomyces, Pichia, and Trichoderma along with two species including Aspergillus oryzae and Pochonia chlamydosporia are comprehensively evaluated and scrutinized. The characteristics of these fungi could be further improved and harnessed for a dual production of biocontrol agents and bioethanol, improving the economic and environmental feasibilities of lignocellulose-based bioethanol production.