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The nitrile hydratase from the mutant strain of Brevibacterium sp. ACV2 was purified and compared to that from the wild type R312. Its molecular weight was estimated at 80000. This enzyme is composed of 2 sub-units with 26000 and 27500 molecular weights. The nitrile hydratase of the mutant strain is different from that of the wild type by its pHi, optimum activity pH, and its rates of hydrolysis of cyanovaleramide and cyanovaleric acid which were 30 and 15 folds greater.

Hydrolysis and transport of maltose into Schwanniomyces castellii was studied under aerobic and anaerobic conditions. Amylase and glucosidase were not synthetized in presence of maltose in anaerobic conditions. Maltose permease was synthesized in anaerobiosis and its functioning is not inhibited. Glucose strongly repressed induction. The half-saturation constant for uptake of maltose was 0.06 mM. The rate of uptake of maltose was decreased by 2,4-dinitrophenol, antimycin or sodium azide. The significance of these results in relation to the Kluyver effect is discussed.

A yeast strain isolated in the laboratory was studied and classified as a Candida molischiana. The β-glucosidase of this yeast strain was then purified. Its molecular weight, estimated by gel filtration, was 100,000. The enzyme consisted of only one subunit, identified after treatment with sodium dodecyl sulfate. Maximum activity was obtained at 55°C and pH 4 but the enzyme still possessed activity at pH 2.5. Active against different glucosides with β(1–2), β(1–3), β(1–4), β(1–6), and α(1–4) configurations it presented an α(1–6)-arabinofuranosidase activity. The enzyme was competitively inhibited by glucose (Ki 9.5 mm). A glucosyltransferase activity appeared in the presence of ethanol. The enzyme was constitutive but its synthesis was repressed by glucose.

A virus-like particle (VLP) of 42 nm diameter was isolated from the lipolytic microorganism Geotrichum candidum. The VLP contains a linear double-stranded RNA molecule of 1.70 μm in length. Proteins of VLP were studied by polyacryl amide gel electrophoresis.

The malolactic enzyme of Leuconostoc oenos ATCC 23278 was purified 136fold. The molecular weight was estimated at 132,000 when determined by gel filtration. The enzyme contained two identical subunits (Mw = 66,000 using sodium dodecyl sulfate gel electrophoresis). The malolactic enzyme catalyzes the NAD(+)- and Mn(+)-dependent reaction L-malate----L-lactate + CO2. The apparent Km values for malic acid, NAD+, and Mn2+ were 17 mM, 0.044 mM, and 0.017 mM, respectively. The optimal pH and the optimal temperature for activity were 5.0, and 37 degrees C, respectively and the isoelectric point was pH 4.30. L-lactate and ethanol were non-competitive inhibitors, whereas succinate, citrate, and D-tartrate showed competitive type inhibitions.

An amidase with a wide activity spectrum was purified from the Brevibacterium sp. R 312 and studied. The purification was performed by precipitating the proteins of the supernatant fraction obtained after centrifugation of sonicated cells. The resulting proteins were submitted to a gel filtration step followed by DEAE-Sephadex ion exchange chromatography and then by another gel filtration process. The purified amidase had a molecular weight of 180,000 and was composed of four subunits of the same molecular weight (43,000 + 2,000). Its isoelectric point was 3.5. This enzyme was able to hydrolyze a large number of amides into their corresponding organic acids and it also possessed an acyl transferase activity.

Besides its nitrile hydratase and wide spectrum amidase activities, the Brevibacterium sp. R312 strain also possesses a constitutive beta-glucosidase. Its optimum pH is 6. The enzyme was purified by fractionation precipitation with ammonium sulfate followed by chromatographic elutions on Q-Sepharose Fast Flow, Sephadex G-200 and Phenyl Superose. The resulting purification was 1960 folds for a 6% yield. The molecular weight of this enzyme was estimated at 180,000. It contains two identical sub-units. The pI is 5.5. This enzyme has a strong affinity for aryl-beta-glycosides:pNPG, prunassine; it could also degrade linamarine. It is inhibited by p-chloromercuribenzoate, delta-gluconolactone and glucose.