Enhanced Biomass Yield of and Saccharification in Transgenic Tobacco Over-Expressing β-Glucosidase.

Eun Jin Cho,Bok Jae Park,Hyeun-Jong Bae,Quynh Anh Nguyen,Younho Song,Yoon Gyo Lee

doi:10.3390/biom10050806

Abstract

Here, we report an increase in biomass yield and saccharification in transgenic tobacco plants (Nicotiana tabacum L.) overexpressing thermostable β-glucosidase from Thermotoga maritima, BglB, targeted to the chloroplasts and vacuoles. The transgenic tobacco plants showed phenotypic characteristics that were significantly different from those of the wild-type plants. The biomass yield and life cycle (from germination to flowering and harvest) of the transgenic tobacco plants overexpressing BglB were 52% higher and 36% shorter than those of the wild-type tobacco plants, respectively, indicating a change in the genome transcription levels in the transgenic tobacco plants. Saccharification in biomass samples from the transgenic tobacco plants was 92% higher than that in biomass samples from the wild-type tobacco plants. The transgenic tobacco plants required a total investment (US$/year) corresponding to 52.9% of that required for the wild-type tobacco plants, but the total biomass yield (kg/year) of the transgenic tobacco plants was 43% higher than that of the wild-type tobacco plants. This approach could be applied to other plants to increase biomass yields and overproduce β-glucosidase for lignocellulose conversion.

Highlights

Lignocellulosic biomass, originating from crops, is abundant and available globally
Vector Construction for the Overexpression of Thermostable β-Glucosidase T. maritima BglB Targeted to the Chloroplasts and Vacuoles in Tobacco Plants and β-Glucosidase Enzymatic Activity
Our results indicated no significant difference between carbohydrate content of biomass samples from wild-type and transgenic tobacco plants at the three sampling points (Table 1), suggesting that other unknown causes might be involved in the enhancement of saccharification

Summary

Introduction

Lignocellulosic biomass, originating from crops, is abundant and available globally. Several studies focusing on plant genetic engineering have aimed to improve the feasibility of biofuel production by reducing the recalcitrant components of plant biomass and increasing the heterologous overexpression of enzymes for the autohydrolysis of cellulose in plants, in order to improve conversion yield [3,4,5]. Another approach is to increase the production of biomass via plant genetic engineering [6,7]. Despite some successes, practical application of this technique has not been confirmed

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