Industrial strains of Rhizopus oryzae is known for its strong ability to produce L-( +)-lactic acid, ethanol, and fumaric acid at high yields. To better understand the underlying mechanism behind the physiology of R. oryzae, we conducted the proteome changes between two different morphologies using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. R. oryzae exhibited pellet morphology and filamentous morphology when the initial pH of the culture medium was 3.0 and 5.0, respectively. The concentration of lactic acid reached 63.5 g L⁻¹ in the samples containing the pellet morphology, compared to 41.5 g L⁻¹ produced by filamentous R. oryzae. Proteomic analysis indicated that expression levels of 128 proteins changed significantly. Of these, 17 protein spots were successfully identified by mass spectrometry and were deemed to be mainly involved in carbohydrate metabolism, genetic information processing, chitin metabolism, protein catabolism, protein folding, and antioxidative pathway. L-lactate dehydrogenase (RO3G_06188), enolase (RO3G_05466) and 2, 3-bisphosphoglycerate-independent phosphoglycerate mutase (RO3G_02462) were found to be upregulated, while isocitrate dehydrogenase (RO3G_13820) was downregulated in the samples with pellet morphology compared to the filamentous hyphae. These results suggested that more carbon flow was directed towards lactic acid biosynthesis in R. oryzae hyphae with pellet morphology.

米根霉工业菌株以其高产 L-(+)-乳酸、乙醇和富马酸的强大能力而闻名。为了更好地理解稻瘟病菌生理学背后的潜在机制，我们使用二维聚丙烯酰胺凝胶电泳和质谱法对两种不同形态之间的蛋白质组变化进行了研究。当培养基的初始 pH 值分别为 3.0 和 5.0 时，米根霉表现出颗粒形态和丝状形态。含有颗粒形态的样品中乳酸浓度达到 63.5 g L ^-1，而丝状稻瘟病菌产生的乳酸浓度为 41.5 g L ^-1. 蛋白质组学分析表明，128 种蛋白质的表达水平发生了显着变化。其中，质谱法成功鉴定出17个蛋白点，主要参与碳水化合物代谢、遗传信息处理、几丁质代谢、蛋白质分解代谢、蛋白质折叠和抗氧化通路。发现 L-乳酸脱氢酶 (RO3G_06188)、烯醇化酶 (RO3G_05466) 和 2, 3-二磷酸甘油酸非依赖性磷酸甘油酸变位酶 (RO3G_02462) 被上调，而异柠檬酸脱氢酶 (RO3G_13820) 与颗粒形态相比，异柠檬酸脱氢酶 (RO3G_13820) 在颗粒形态下被下调. 这些结果表明，更多的碳流被导向具有颗粒形态的米根霉菌丝中的乳酸生物合成。