Two Bacillus Species Isolated from Rotting Wood Samples are Good Candidates for the Production of Bioethanol using Agave Biomass

Yagya Prasad Paudel Wensheng Qin

doi:10.4172/1948-5948.1000210

Abstract

The biorefining of crop and plant organic matter represents a promising route to produce renewable fuels and bioproducts. The high contents of cellulose and hemicellulose make Agave americana an ideal candidate to produce value-added products. In this study, two different cellulase producing bacteria, isolated from rotting wood samples, were incubated and cultivated to examine their ability to decompose agave and produce ethanol. The results showed the transparent zones called halos on the plates containing Agave as the sole carbon source after iodine staining for these two isolates and positive control Cellulomonas xylanilytica; while, no halo was observed for negative control: Escherichia coli BL21. The Bacillus species K1 and A0 displayed hydrolysis ability greater than that of positive control based on halo diameter. Moreover, the quantitative ability to decompose agave was studied for the same two bacterial strains using minimal salt media containing 5% agave biomass. Dinitrosalicylic acid (DNS) method was used to detect cellulase and reducing sugars. Ethanol was detected by using micro-dichromate method. The results showed that strain K1 produced 0.435 g ethanol/g Agave biomass and the isolate A0 produced 0.397 g/g ethanol on the 4th day of incubation.

Highlights

With the exhaustion of non-renewable fossil fuels leading to environmental pollution and energy crisis, there is a demand for new renewable sources of energy
Cellulase screening using Agave as the source of carbon. Both the bacterial strains showed the area of depolymerisation which proved their ability for hydrolysis of Agave biomass (Figure 1A)
The hydrolysis ability values for strains K1 and A0 are 19.04 and 14.27. This showed that both the bacteria have better ability than C. xylanilytica for hydrolysis of Agave biomass

Summary

Introduction

With the exhaustion of non-renewable fossil fuels leading to environmental pollution and energy crisis, there is a demand for new renewable sources of energy. Bioethanol is the biofuel mostly useful for transportation worldwide. It can be produced from different raw materials such as simple sugars, starch, agricultural products, and lignocellulosic biomass. It might be beneficial to use renewable plant materials for bio-fuel, the use of crop residues and other biomass for bio-fuels raises many concerns about major environmental problems such as food shortages and serious destruction of vital soil resources [2]. The availability of raw materials for the production is one of the major problems associated with the bioethanol production. To overcome this problem, lignocellulosic biomass constitutes the world’s largest bioethanol renewable source. The main reason for this is the production cost of bioethanol from lignocellulose is too high due to enzyme production cost

Objectives

Methods

Results

Conclusion