{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,19]],"date-time":"2026-03-19T16:58:20Z","timestamp":1773939500515,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"5","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1972,8,1]]},"abstract":"<jats:p>Azotobacter beijerinckii was grown in ammonia-free glucose\u2013mineral salts media in batch culture and in chemostat cultures limited by the supply of glucose, oxygen or molecular nitrogen. In batch culture poly-\u03b2-hydroxybutyrate was formed towards the end of exponential growth and accumulated to about 74% of the cell dry weight. In chemostat cultures little poly-\u03b2-hydroxybutyrate accumulated in organisms that were nitrogen-limited, but when oxygen limited a much increased yield of cells per mol of glucose was observed, and the organisms contained up to 50% of their dry weight of poly-\u03b2-hydroxybutyrate. In carbon-limited cultures (D, the dilution rate,=0.035\u20130.240h\u22121), the growth yield ranged from 13.1 to 19.8g\/mol of glucose and the poly-\u03b2-hydroxybutyrate content did not exceed 3.0% of the dry weight. In oxygen-limited cultures (D=0.049\u20130.252h\u22121) the growth yield ranged from 48.4 to 70.1g\/mol of glucose and the poly-\u03b2-hydroxybutyrate content was between 19.6 and 44.6% of dry weight. In nitrogen-limited cultures (D=0.053\u20130.255h\u22121) the growth yield ranged from 7.45 to 19.9g\/mol of glucose and the poly-\u03b2-hydroxybutyrate content was less than 1.5% of dry weight. The sudden imposition of oxygen limitation on a nitrogen-limited chemostat culture produced a rapid increase in poly-\u03b2-hydroxybutyrate content and cell yield. Determinations on chemostat cultures revealed that during oxygen-limited steady states (D=0.1h\u22121) the oxygen uptake decreased to 100\u03bcl h\u22121 per mg dry wt. compared with 675 for a glucose-limited culture (D=0.1h\u22121). Nitrogen-limited cultures had CO2 production values in situ ranging from 660 to 1055\u03bcl h\u22121 per mg dry wt. at growth rates of 0.053\u20130.234h\u22121 and carbon-limited cultures exhibited a variation of CO2 production between 185 and 1328\u03bcl h\u22121 per mg dry wt. at growth rates between 0.035 and 0.240h\u22121. These findings are discussed in relation to poly-\u03b2-hydroxybutyrate formation, growth efficiency and growth yield during growth on glucose. We suggest that poly-\u03b2-hydroxybutyrate is produced in response to oxygen limitation and represents not only a store of carbon and energy but also an electron sink into which excess of reducing power can be channelled.<\/jats:p>","DOI":"10.1042\/bj1281193","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T19:44:32Z","timestamp":1439235872000},"page":"1193-1201","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":165,"title":["The role of oxygen limitation in the formation of poly-\u03b2-hydroxybutyrate during batch and continuous culture of <i>Azotobacter beijerinckii<\/i>"],"prefix":"10.1042","volume":"128","author":[{"given":"P. J.","family":"Senior","sequence":"first","affiliation":[{"name":"Department of Biochemistry, University of Hull, Kingston upon Hull HU6 7RX, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G. A.","family":"Beech","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of Hull, Kingston upon Hull HU6 7RX, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"G. A. F.","family":"Ritchie","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of Hull, Kingston upon Hull HU6 7RX, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E. A.","family":"Dawes","sequence":"additional","affiliation":[{"name":"Department of Biochemistry, University of Hull, Kingston upon Hull HU6 7RX, U.K."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/128\/5\/1193\/778196\/bj1281193.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/128\/5\/1193\/778196\/bj1281193.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,26]],"date-time":"2021-11-26T14:56:17Z","timestamp":1637938577000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/128\/5\/1193\/7481\/The-role-of-oxygen-limitation-in-the-formation-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1972,8,1]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1972,8,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1281193","relation":{},"ISSN":["0306-3283"],"issn-type":[{"value":"0306-3283","type":"print"}],"subject":[],"published":{"date-parts":[[1972,8,1]]}}}