Characterization of an Acetobacter Strain Isolated from Iranian Peach that Tolerates High Temperatures and Ethanol Concentrations

Vinegar is a precious food additive and complement as well as effective preservative against food spoilage. Recently traditional vinegar production has been improved using various natural substrates and fruits such as grape, palm, cherry, coconut, date, sugarcane, rice and balsam. These neoclassical fermentations resulted in several vinegar types with different tastes, fragrances and nutritional values because of applying various acetic acid bacteria as starters. Acetic acid bacteria include genera Acetobacter, Gluconacetobacter and Gluconobacter according to latest edition of Bergy-s Manual of Systematic Bacteriology that classifies genera on the basis of their 16s RNA differences. Acetobacter spp as the main vinegar starters belong to family Acetobacteraceae that are gram negative obligate aerobes, chemoorganotrophic bacilli that are oxidase negative and oxidize ethanol to acetic acid. In this research we isolated and identified a native Acetobacter strain with high acetic acid productivity and tolerance against high ethanol concentrations from Iranian peach as a summer delicious fruit that is very susceptible to food spoilage and decay. We used selective and specific laboratorial culture media such as Standard GYC, Frateur and Carr medium. Also we used a new industrial culture medium and a miniature fermentor with a new aeration system innovated by Pars Yeema Biotechnologists Co., Isfahan Science and Technology Town (ISTT), Isfahan, Iran. The isolated strain was successfully cultivated in modified Carr media with 2.5% and 5% ethanol simultaneously in high temperatures, 34 - 40º C after 96 hours of incubation period. We showed that the increase of ethanol concentration resulted in rising of strain sensitivity to high temperature. In conclusion we isolated and characterized a new Acetobacter strain from Iranian peach that could be considered as a potential strain for production of a new vinegar type, peach vinegar, with a delicious taste and advantageous nutritional value in food biotechnology and industrial microbiology.

• K. Beheshti Maal
• R. Shafiee

• Acetobacter
• Acetic Acid Bacteria
• Vinegar
• Peach
• Food Biotechnology
• Industrial Microbiology
• Fermentation

[1] G. S. Kocher, K. L. Kalra and R. P. Phutela, "Comparative production of
sugarcane vinegar by different immobilization techniques," J. Inst.
Brew., vol. 112, 2006, pp.264-266.
[2] K. Beheshti Maal and R. Shafiee, "Isolation and characterization of an
Acetobacter strain fro Iranian white-red cherry as a potential strain for
cherry vinegar production in microbial biotechnology," Asian J.
Biotechnol., vol. 1, 2010, pp.53-59.
[3] T. T. Kadere, T. Miamoto, R. K. Oniang-o, P. M. Kutima and S. M.
Njoroge, "Isolation and identification of genera Acetobacter and
Gluconobacter in coconut toddy (mnazi)," Afr. J. Biotechnol., vol. 7,
2008, pp.2963-2971.
[4] J. G. Holt, N. R. Krieg, P. H. A. Sneath, J. T. Staley and S. T. Williams,
"Bergey-s Manual of Determinative Bacteriology," New York, Williams
and Wilkins, 1994, pp.267-279.
[5] M. T. Madigan, J. M. Martinko, P. V. Dunlap and D. P. Clark, "Brock
Biology of Microorganisms" New York, Benjamin Cummings, 2008,
pp.260-391.
[6] A. Ruiz, M. Poblet, A. Mas and J. M. Guillamon, "Identification of
acetic acid bacteria by RFLP of PCR-amplified 16S rDNA and 16S-23S
rDNA intergenic spacer," Int. J. Syst. Microbiol., vol. 50, 2000,
pp.1981-1987.
[7] S. J. Sokollek, C. Hertel and W. P. Hammes, "Cultivation and
preservation of vinegar bacteria," J. Biotechnol., vol. 60, 1998, pp.195-
206.
[8] W. J. Du Toit and M. G. Lambrechts, "The enumeration an identification
of acetic acid bacteria from South African red wine fermentations," Int.
J. Food Microbiol., vol. 74, 2002, pp.57-64.
[9] S. I. Faparusi, "Origin of initial microflora of palm wine from oil palm
trees (Elaeis guineensis)," J. Appl. Bacteriol., vol. 36, 1973, pp.559-565.
[10] N. Okafar, "Microbiology of Nigerian palm wine with particular
reference to bacteria," J. Appl. Bacteriol., vol. 38, 1975, pp.81-88.
[11] A. Moryadee and W. Pathon-Aree, "Isolation of thermotolerant acetic
acid bacteria from fruits for vinegar production," Res. J. Microbiol., vol.
3, 2008, pp.209-212.
[12] S. K. Sossou, Y. Ameyapoh, S. D. Karou and C. D. Souza, "Study of
pineapple peelings processing into vinegar by biotechnology," Pak. J.
Biol. Sci., vol. 11, 2009, pp.859-865.
[13] A. Joyeux, S. Lafon-Lafourcade and P. Ribereau-Gayon, "Evolution of
acetic acid bacteria during fermentation and storage of wine," Appl.
Environ. Microbiol., vol. 48, 1984, pp.153-156.
[14] G. S. Drydale and G. H. Fleet, "Acetic acid bacteria in some Australian
wines," Food Technol. Aust., vol. 37,1985, pp.17-20.
[15] P. Giudici and G. Rinaldi, "A theoretical model to predict the age of
traditional balsamic vinegar," J. Food Eng., vol. 82, 2007, pp.121-127.
[16] M. Gullo and P. Giudici, "Acetic acid in traditional balsamic vinegar,
phenotypic traits relevant for starter cultures selection," Int. J. Food
Microbiol., vol. 125, 2008, pp.46-53.
[17] P. M. Falcone and P. Giudici, "Molecular size and molecular size
distribution affecting traditional balsamic vinegar aging," J. Agri. Food
Chem., vol. 56, 2008, pp.7057-7066.
[18] K. Nanda, M. Taniguchi, S. Ujike, N. Ishihara, H. Mori, H. Ono and Y.
Murooka, "Characterization of acetic acid bacteria in traditional acetic
acid fermentation of rice vinegar (komesu) and unpolished rice vinegar
(kurosu) produced in Japan," Appl. Environ. Microbiol., vol. 67, 2001,
pp.986-990.
[19] E. C. IIha, E. S. Anna, R. C. Torres, A. C. Porto and E. M. Meinert,
"Utilization of bee (Apis mellifera) honey for vinegar production at
laboratory scale," Acta Cie. Ven., vol. 51, 2000, pp.231-235.
[20] B. Ndoye, L. Cleenwerck, K. Engelbeen, R. Dubois-Dauphin, A. T.
Guiro, S. V. Trappen, A. Willems and P. Thonart, "Acetobacter
senegalensis sp. nov., a thermotolerant acetic acid bacterium isolated in
Senegal (sub-Saharan Africa) from mango fruit (Mangifera indica L.),"
Int. J. Syst. Evol. Microbiol., vol. 57, 2007, pp.1576-1581.