Influence of the Metabolism Pathway on Lactic Acid Production from Hemicellulosic Trimming Vine Shoots Hydrolyzates Using Lactobacillus pentosus

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• 作者：Guadalupe Bustos ; Ana Belé ; n Moldes ; José ; Manuel Cruz ; and José ; Manuel Dom&iacute ; nguez
• 刊名：Biotechnology Progress
• 出版年：2005
• 出版时间：June 2005
• 年：2005
• 卷：21
• 期：3
• 页码：793 - 798
• 全文大小：171K
• 年卷期：v.21,no.3(June 2005)
• ISSN：1520-6033

文摘

Hemicellulosic hydrolyzates from trimming wastes of vine shoots were proposed as acarbon source for lactic acid production by Lactobacillus pentosus CECT-4023T (ATCC-8041). These hydrolyzates are composed mainly of glucose (12.0 g/L), xylose (17.5 g/L)and arabinose (4.3 g/L). Acetic acid, the main subproduct, started to be produced afterall of the glucose was completely depleted, showing that the acetic acid coproductioncame only from the xylose and arabinose consumption. In the absence of glucose, theL. pentosus pathway shifts from homo to heterofermentative. Thus, L. pentosus canbe considered a facultative heterofermentative organism, degrading hexoses (glucose)via the Embden-Meyerhoff-Parnas pathway and pentoses (xylose and arabinose) viathe phosphoketolase pathway. Hydrolyzates were vacuum evaporated to increase theinitial sugars concentration up to 35.4 g/L of glucose, 52.3 g/L of xylose, and 13.0 g/Lof arabinose. Under these conditions the lactic acid concentration reached 46.0 g/L(Q_P = 0.933 g/L·h, Y_P/S = 0.78 g/g; Y_P/S theoretical = 91.7%) and a clear productinhibition was observed. Additional experiments with synthetic sugars, in the absenceof inhibitory compounds, indicate that this inhibition must be attributed to themetabolic pathway but not to the inhibitory compounds present in the fermentationbroth.