Microalgal and/or cyanobacterial biomass could be more advantageous than current plant feedstocks for the production of ethanol and/or other fermentation products. Enzymatic saccharification of microalgal biomass currently requires harsh pretreatments and significant amounts of expensive hydrolytic enzymes. The purpose of this study was: i) to analyze the quality of biomass of a cell-wall deficient microalga as a saccharification substrate for enzymatic hydrolysis; and ii) to identify an alternative source of enzymes for the saccharification of algal biomass. We showed that a newly isolated strain of the fungus Trichoderma harzianum was able to grow at the expense of intact cells of the alga Chlamydomonas reinhardtii as a sole source of nutrients. The fungal spent medium exhibited pectinolytic, amylolytic, cellulolytic, and proteolytic activities and efficiently saccharified either dry and milled biomass or intact cells of the microalga. Biomass of a cell-wall deficient C. reinhardtii strain was saccharified at a similar efficiency than biomass of the parental strain with T. harzianum enzymes, indicating full capacity of these enzymes to circumvent the cell-wall recalcitrance to hydrolysis. Algal biomass saccharification yielded up to 22.4 g reducing sugars·L⁻¹ and could be quantitatively converted into ethanol by fermentation with Saccharomyces cerevisiae. The efficiency of conversion of algal biomass into ethanol showed in this study is among the highest reported so far and encourages research for scaling up production of T. harzianum enzymes as well as the evaluation of biomass of other algal strains as feedstocks for the production of ethanol.

对于乙醇和/或其他发酵产物的生产，微藻和/或蓝细菌生物质可能比当前的植物原料更具优势。微藻生物质的酶糖化目前需要严格的预处理和大量昂贵的水解酶。这项研究的目的是：i）分析细胞壁不足的微藻作为酶促水解糖化底物的生物质的质量；和二），以识别酶的替代来源为藻类生物质的糖化。我们表明，新分离出的真菌木霉哈茨木霉菌能够以藻类莱茵衣藻完整细胞为代价生长作为唯一的营养来源。真菌用过的培养基表现出果胶分解，淀粉分解，纤维素分解和蛋白水解活性，并有效地糖化了干燥和碾碎的生物量或完整的微藻细胞。用哈茨木霉菌酶将细胞壁缺陷的莱茵衣藻菌株的生物质糖化的效率与亲本菌株的生物质相似，表明这些酶具有完全的能力来规避细胞壁对水解的抵抗性。藻类生物质糖化可产生高达22.4 g的还原糖·L ^-1，并且可以通过酿酒酵母发酵而定量地转化为乙醇。这项研究表明，藻类生物质转化为乙醇的效率是迄今为止报道的最高效率之一，并鼓励进行扩大规模的哈茨木霉酶生产以及评估其他藻类菌株生物质作为乙醇生产原料的研究。 。