Acetobacter species preparation

In 1973 the structure (157) or (158) was proposed for a C35 hopane derivative, bacteriohopanetetrol, from the bacterium Acetobacter xylinum. Structure (157) is attractive as a precursor for the extended hopane derivatives obtained from geological sources (see Vol. 3, p. 228 and Vol. 5, p. 145). Rohmer and Ourisson have now confirmed"" the validity of (157) and have shown the presence of both (22R)- and (225)-epimers. Periodate cleavage of the tetrol followed by sodium borohydride reduction and acetylation afforded the epimeric acetates (159) identical with synthetic samples prepared from diploptene (160). A range of Acetobacter species and... 

Cells for Increasing Fermenter Efficiencies. The tower fermenter system used is described in Figure 3. Wort was used as the ethanol source, and an inociilum of an aggregating strain of Acetobacter species was prepared and added to the tower fermenter (2 litres capacity). When the level of acetic acid in the fermenter had reached about 3% w/v, the medium delivery pump was started and the flow rate adjusted to a level that gave almost complete conversion of the ethanol available into acetic acid. Undue haste in increasing the flow rate and also serious decrease or stoppage of the air flow caused the expected fall in conversion efficiency. Adjustment of the flow and aeration rate showed that a maximum V. E. of 0.82 could be attained (see Table I). 

Interpretation Formation of bubbles is generally indicative of the presence of catalase and, hence, oxidative metabolism. In the case of wine bacteria, such a reaction is characterized by either Acetobacter or Glucono-bactersp. In some weakly catalase positive species, bubbling is difficult to observe. In these cases, carefully place a coverslip over the preparation and... 

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