Transcriptional analysis of genes for energy catabolism and hydrolytic enzymes in the filamentous fungus Aspergillus oryzae using cDNA microarrays and expressed sequence tags
Transcriptional analysis of genes for energy catabolism and hydrolytic enzymes in the filamentous fungus Aspergillus oryzae using cDNA microarrays and expressed sequence tags
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DOI：
10.1007/s00253-004-1608-4
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发表时间：
2004-07-01
影响因子：
5
通讯作者：
Iguchi, Y
中科院分区：
文献类型：
--
作者：
Maeda, H;Sano, M;Iguchi, Y
黑曲霉是发酵工业中广泛使用的真菌。我们构建了包含2,070个高表达cDNA的cDNA微阵列，这些cDNA是从A.数据库（http：//www.aist.go.jp/RIODB/ffdb/index.html）。利用cDNA微阵列技术，我们分析了A.在EST数据库构建过程中使用的富葡萄糖（AC）和葡萄糖耗尽（AN）液体培养条件下生长的细胞。由cDNA微阵列鉴定的在每种培养条件下高表达的基因组与在相同条件下获得的高度冗余的EST一致。特别是糖酵解途径（EMP）和三羧酸（TCA）循环的大多数分解代谢基因在AC条件下的转录水平高于AN条件，表明A.在AC条件下，EMP和TCA均用于葡萄糖代谢。我们进一步研究了编码水解酶和参与能量催化的酶的基因的表达，通过使用三种工业固相生物质培养基，包括小麦麸皮。小麦麸皮培养物中水解酶基因表达谱最丰富，分解代谢基因（EMP、TCA）表达水平最低。小麦麸皮培养物中分解代谢基因的低表达水平可能会释放分解代谢物阻遏，从而导致水解酶的丰富表达谱。
Aspergillus oryzae is a fungus used extensively in the fermentation industry. We constructed cDNA microarrays comprising 2,070 highly expressed cDNAs selected from the similar to6,000 non-redundant expressed sequence tags (ESTs) in the A. oryzae EST database (http://www.aist.go.jp/RIODB/ffdb/index.html). Using the cDNA microarrays, we analyzed the gene expression profiles of A. oryzae cells grown under the glucose-rich (AC) and glucose-depleted (AN) liquid culture conditions used during the construction of the EST database. The sets of genes identified by the cDNA microarray as highly expressed under each culture condition agreed well with the highly redundant ESTs obtained under the same conditions. In particular, transcription levels of most catabolic genes of the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle were higher under AC than AN conditions, suggesting that A. oryzae uses both EMP and TCA for glucose metabolism under AC conditions. We further studied the expression of genes encoding hydrolytic enzymes and enzymes involved in energy catabolism by using three industrial solid-phase biomass media, including wheat-bran. The wheat-bran culture gave the richest gene expression profile of hydrolytic enzymes and the lowest expression levels of catabolic genes (EMP, TCA) among the three media tested. The low expression levels of catabolic genes in the wheat-bran culture may release catabolite repression, consequently leading to the rich expression profiles of the hydrolytic enzymes.