Sheikh Md Mominul Islam, Kim Chul-Hwan, Park Hyeong-Hun, Nam Hye-Gyeong, Lee Gyeong Sun, Jo Hu Seung, Lee Ji-Young, Kim Jae Won
Department of Environmental Material Science, IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
J Sci Food Agric. 2015 Mar 15;95(4):843-50. doi: 10.1002/jsfa.7004. Epub 2014 Dec 9.
Barley straw (Hordeum vulgare L.) is an attractive lignocellulosic material and one of the most abundant renewable resources for fuel ethanol production. Although it has high cellulose and hemicellulose contents, there are several challenges and limitations in the process of converting it to fuel ethanol. High ash, silica and lignin contents in barley straw make it an inferior feedstock for enzymatic hydrolysis. Therefore pretreatment of barley straw could play an important role in inducing structural and compositional changes that increase the efficiency of enzymatic hydrolysis and make the whole process economically viable.
Saccharification was enhanced using various concentrations (0.0, 0.5, 1.0, 2.0 and 3.0% v/v) of a solution of sodium hypochlorite (NaClO) and hydrogen peroxide (H₂O₂) and various reaction times (15, 30 and 45 min) during pretreatment at 121 °C. The highest yield of glucose (447 mg g⁻¹) was achieved by pretreatment with 2.0% NaClO+H₂O₂ solution for 30 min, representing an increase of 65.99% compared with untreated barley straw (152 mg g⁻¹). During fermentation, the highest amount of ethanol (207 mg g⁻¹) was obtained under anaerobic plus 0.4 mmol L⁻¹ benzoic acid conditions, representing an increase of 57.49, 38.16 and 10.14% compared with untreated sample (88 mg g⁻¹), aerobic (128 mg g⁻¹) and anaerobic (186 mg g⁻¹) conditions respectively.
The results suggest that pretreatment with 2.0% NaClO+H₂O₂ solution disrupted the recalcitrant structure of barley straw and enhanced the glucose yield and subsequent bioethanol production.
大麦秸秆（Hordeum vulgare L.）是一种具有吸引力的木质纤维素材料，也是用于燃料乙醇生产的最丰富的可再生资源之一。尽管其纤维素和半纤维素含量较高，但将其转化为燃料乙醇的过程中存在若干挑战和限制。大麦秸秆中高含量的灰分、二氧化硅和木质素使其成为酶水解的劣质原料。因此，大麦秸秆的预处理对于诱导结构和成分变化具有重要作用，这些变化可提高酶水解效率并使整个过程在经济上可行。
在121°C预处理期间，使用不同浓度（0.0、0.5、1.0、2.0和3.0% v/v）的次氯酸钠（NaClO）和过氧化氢（H₂O₂）溶液以及不同反应时间（15、30和45分钟）可提高糖化率。用2.0% NaClO+H₂O₂溶液预处理30分钟可实现最高葡萄糖产量（447 mg g⁻¹），与未处理的大麦秸秆（152 mg g⁻¹）相比增加了65.99%。在发酵过程中，在厌氧加0.4 mmol L⁻¹苯甲酸条件下获得了最高乙醇量（207 mg g⁻¹），与未处理样品（88 mg g⁻¹）、好氧（128 mg g⁻¹）和厌氧（186 mg g⁻¹）条件相比分别增加了57.49%、38.16%和10.14%。
结果表明，用2.0% NaClO+H₂O₂溶液预处理破坏了大麦秸秆的顽固结构，提高了葡萄糖产量及后续生物乙醇产量。
