Detection of NAD super(+)-Dependent Alcohol Dehydrogenase Activities in YR-1 Strain of Mucor circinelloides, a Potential Bioremediator of Petroleum Contaminated Soils

• Published in: Applied biochemistry and biotechnology 2005-03, Vol.121 (1-3), p.0279-0288
• Main Authors: Duron-Castellanos, A, Zazueta-Novoa, V, Silva-Jimenez, H, Alvarado-Caudillo, Y, Cabrera, E P, Zazueta-Sandoval, R
• Format: Article
• Language: English
• Subjects: Mucor circinelloides
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1385/ABAB:121:1-3:0279

Different soluble NAD super(+)-dependent alcohol dehydrogenase (ADH) isozymes were detected in cell-free homogenates from aerobically grown mycelia of YR-1 strain of Mucor circinelloides isolated from petroleum- contaminated soil samples. Depending on the carbon source present in the growth media, multiple NAD super(+)-dependent ADHs were detected when hexadecane or decane was used as the sole carbon source in the culture media. ADH activities from aerobically or anaerobically grown mycelium or yeast cells, respectively, were detected when growth medium with glucose added was the sole carbon source; the enzyme activity exhibited optimum pH for the oxidation of different alcohols (methanol, ethanol, and hexadecanol) similar to that of the corresponding aldehyde ( similar to 7.0). Zymogram analysis conducted with partially purified fractions of extracts from aerobic mycelium or anaerobic yeast cells of the YR-1 strain grown in glucose as the sole carbon source indicated the presence of a single NAD super(+)-dependent ADH enzyme in each case, and the activity level was higher in the yeast cells. ADH enzyme from mycelium grown in different carbon sources showed high activity using ethanol as substrate, although higher activity was displayed when the cells were grown in hexadecane as the sole carbon source. Zymogram analysis with these extracts showed that this particular strain of M. circinelloides has four different isozymes with ADH activity and, interestingly, one of them, ADH4, was identified also as phenanthrene-diol- dehydrogenase, an enzyme that possibly participates in the aromatic hydrocarbon biodegradation pathway.