Abstract:
Isolation, identification and the applications in acetic acid and cellulose production of the strains from fruits were studied. One hundred and forty eight strains were isolated from 34 kinds of fruits. They produced aectic acid ranged from 0.01-1.45 g/100 ml. Twelve strains could produce cellulose. The strains which produced high yield of acetic acid and cellulose were selected for applications. Based on morphological, cultural, physiological, biochemical characteristics, and ubiquinone system, the selected 74 strains were separated in 4 groups (3 genus). Group 1 (45 strains) were identified as acetobacter pasteurianus and Group 2 (13 strains) were A. aceti. These two groups contained ubiquinone with 9 isoprene unit (Q-9) as the major component. Group 3 (12 strains) were identified as gluconoacetobacter xylinus and Group 4 (4 strains) were gluconobacter sp. These two group had Q-10 as the major ubiquinone. The distribution of species of acctic acid bacteria was not depended on the total soluble solid in fruits. Acetic acid production from 5 selected strains of A. pasteurianus GR 24-2, Or 56-1, BS 58-2, MG 69-2 and A.aceti SF 18-1 were compared with acetobacter aceti subsp. aceti TISTR 354T and A.pasteurianus TISTR 1056T. Concentration of ethanol, acetic acid, casamino acid, and tempreature affected on acetic production. The results showed that selected strains produced the highest amount of acetic acid at 4.0% (v/v) ethanol, 0.5 or 1.0% (v/v) aceti acid, 0.5% (w/v) casamino acid and at 30-37ํC. At 40ํC, strain OR 56-1 could produce acetic acid at the relative fermentation ratc of 69.5% compared withthe rate at 30ํC in the third day of fermentation. Cellulose production of 6 selected strains of gluconoacetobacter xylinus BB150-1, MM151-1, JF152-1, BS153-1, AP154-1, and LD155-1 was compared with gluconoacetobacter xylinus TISTR 893 in coconut juice medium containing 0.05% of ammonium dihydrogen phosphate, 0.05% magnesium sulfate, 5.00% ethanol, 5.00% sucrose, and 100 ml. coconut juice. The thickness of cellulose produced was measured by vernier caliper every 3 days. At th end of fermentation, the wet weight, dry weight and texture of cellulose pellicles were analysed. Penctration force of cellulose was measured using texture analyzer. The results showed that thickness and penetration force were not significantly different (P<=0.05).