Evaluation of chemical and fermentation parameters during the preparation of wine from berry (Maesobotyra standii)

Amilky red wine was produced from locally sourced berry (Maesobotyra standii) in Abraka, Delta State, Nigeria using innate wild yeast (Saccharomyces cerevisiae) augmented with baker’s yeast activated with 2, 5 and 10% (w/v) sugar solutions in activated yeast: fruit extract ratios of 1:2 and 1:3. It was observed that there was an inverse proportional relationship between percentage (%) titratable acidity and pH as well as for specific gravity (SG) and percentage (%) alcohol for 48 h after which both SG and % alcohol increased. Diauxic growth and malo-lactic fermentation were observed. Total aerobic counts followed same trend as for % alcohol. pH, % titratable acidity, specific gravity, % alcohol and total aerobic counts at 72 h fermentation ranged from 4.85 - 5.85, 0.955 - 1.152, 0.956 - 1.141, 0.54 - 2.62 and 0.95 - 185 x 103 cfu/ml, respectively. The baker’s yeast activated with 5% (w/v) granulated sugar was most suitable for home or commercial berry wine production which gave wine with lower alcoholcontent (1.84%, v/v alcohol) using 1:2 activated baker’s yeast : fruit extract ratio; it gave wine with slightly higher alcohol-content (2.62%, v/v alcohol) with 1:3 baker’s yeast : fruit extract ratio. Thus portable and/or commercial wine can be produced from berry (M. standii) with baker’s yeast activated with 5% (w/v) granulated sugar.Key words: Berry wine, sugar, baker’s yeast, malo-lactic, fermentation

Modification of Bacillus cereus and Pseudomonas aeruginosa isolated from a petroleum refining effluent for increased petroleum product degradation

Bacillus cereus and Pseudomonas aeruginosa isolated from Kaduna refining and petrochemical company (KRPC) were subjected to ultra-violet (UV)-irradiation for 30 min followed by nitrous acid treatment and re-irradiated with UV light for 30 min using standard methods and their petroleum degradation abilities were compared with parent strains. Prior to modification, B. cereus and P.aeruginosa grew on minimal basal medium containing 1.5 and 1% crude oil, respectively, initially but on re-inoculation, both organisms grew on minimal basal medium containing 5% crude oil. 99.83 (0.17% survival) and 96.91% (3.08% survival) death were recorded on UV-irradiation for 30 min; 38.24 (61.76% survival) and 82.02% (10.98% survival) death were recorded after nitrous acid treatment and 29.01 (70.99% survival) and 95.76% (4.24% survival) death were observed on re-irradiation with UV light for 30 min for B. cereus and P. aeruginosa, respectively. Petroleum product degradation increased from98.92% for parent B. cereus to 99.70% for UV-irradiated nitrous acid treated B. cereus, and from 91.34% for parent P. aeruginosa to 98.09% for UV-irradiated nitrous acid treated P. aeruginosa. However, itdecreased from 98.92 to 97.87% and increased from 91.34 to 97.87% for parents and second stage mutants re-irradiated with UV light of B. cereus and P. aeruginosa, respectively. Higher potential were observed for second stage mutant of B. cereus than P. aeruginosa. Thus, the modification of the organisms with UV-irradiation for 30 min followed by nitrous acid treatment resulted in their increased petroleum product degradation ability and could therefore be used for bioremediation of environmentspolluted with petroleum products of 1 - 5% (v/v)