Shaw P D, DeAngelo A B
J Bacteriol. 1969 Aug;99(2):463-8. doi: 10.1128/jb.99.2.463-468.1969.
The metabolism of inorganic nitrogen compounds was studied in extracts of Penicillium atrovenetum which had been grown under conditions in which beta-nitropropionic acid (BNP) synthesis varied from 0 to 12.5 mumoles per ml. None of the extracts was able to oxidize ammonium ion or nitrite. An enzyme was detected which catalyzed the oxidation of hydroxylamine with cytochrome c as the electron acceptor. The activity of this enzyme was not related to the ability of the organism to produce BNP. Nitrate and nitrite reductase activities were detected only in P. atrovenetum cultures grown on nitrate as a nitrogen source. These results indicated that BNP synthesis is probably not directly associated with the metabolism of inorganic nitrogen compounds and that an organic pathway for the formation of the nitro group is more likely. The activities of certain enzymes related to the metabolism of aspartic acid were investigated. Aspartate ammonia-lyase activity could not be detected in P. atrovenetum extracts. Aspartate aminotransferase and glutamate dehydrogenase activities were found in the extracts but were highest in the cultures which did not produce BNP. beta-Nitroacrylic acid reductase activity was highest in extracts of cultures which were actively synthesizing BNP.
对在不同条件下生长的黑曲霉提取物中的无机氮化合物代谢进行了研究，在这些条件下，β-硝基丙酸（BNP）的合成量从每毫升0到12.5微摩尔不等。所有提取物均无法氧化铵离子或亚硝酸盐。检测到一种以细胞色素c作为电子受体催化羟胺氧化的酶。该酶的活性与生物体产生BNP的能力无关。仅在以硝酸盐作为氮源生长的黑曲霉培养物中检测到硝酸盐和亚硝酸盐还原酶活性。这些结果表明，BNP的合成可能与无机氮化合物的代谢没有直接关联，并且硝基形成的有机途径更有可能。研究了与天冬氨酸代谢相关的某些酶的活性。在黑曲霉提取物中未检测到天冬氨酸氨裂解酶活性。在提取物中发现了天冬氨酸转氨酶和谷氨酸脱氢酶活性，但在不产生BNP的培养物中活性最高。β-硝基丙烯酸还原酶活性在积极合成BNP的培养物提取物中最高。
