Technical Session 10: Microbiology I Session
Guangtian Zhou, School of Food and Bio-engineering,Shandong Institute of Light Industry, 250353, Jinan, Shandong, China
Co-author(s): Xinxia Ge, School of Food and Bioengineering, Shandong
Institute of Light Industry, Jinan, China; Wen He and Xiaoyong Du, Key
Laboratory of Glass and Functional Ceramics, Shandong Polytechnic
University, Jinan, China; Xiaolei Dong, School of Food and
Bioengineering, Shandong Institute of Light Industry, Jinan, China
ABSTRACT: Hygiene is a major concern of the brewing
industry. The aim of this study was to examine the antimicrobial effect
of mesoporous zirconium phosphate (M-Zrp), which is an inorganic
nanometer material with an aperture of 2~50 nm that could be used as an
effective antibacterial agent against beer-spoilage bacteria. Template
synthesis of M-Zrp is an important method. A biological template has a
lot of advantages in terms of non-toxic and environmental protection.
M-Zrp’s were produced by natural fresh yeast through bio-mimetic
synthesis, which conforms to the green chemical concept advocated at the
present. The antibacterial activity of M-Zrp from the yeast bio-
template was investigated by the inhibition zone test. The impact of
particle size, concentration, and action time on antibacterial behavior
was examined. The results showed that M-Zrp has bacteriostatic activity
against Saccharomyces diastaticus, Candida albicans, Pediococcus damnosus, and Escherichia coli. But it had no effect on Lactobacillus brevis and Pectinatus cerevisiiphilus.
The mean diameters of the inhibition zone were 11.67, 12.37, 8.64, and
14.36 mm, respectively. Antibacterial activity increased as the
concentration of M-Zrp increased and particle size decreased. Within a
certain range, the effect was enhanced with the prolonging of action
time. The minimal inhibitory concentrations (MIC) were found by
spectroscopic method to be 10 mg/L for S. diastaticus, C. albicans, and E. coli, and 25 mg/L for P. damnosus.
When M-Zrp was exposed to bacteria for 24 hr, the average sterilization
rate can reach 96.78% at MIC of 12.5 mg/L and up to 98.54% after 36 hr.
The morphology of S. diastaticus before and after treatment with
M-Zrp was observed by means of polarization microscope. It was observed
that the presence of M-Zrp damages the membrane of the bacterium at
first, and further, penetrates the cell wall and interacts with internal
components, resulting in leakage of intracellular contents and
eventually the death of bacterial cells. Our findings suggest that M-Zrp
exhibits effective antimicrobial properties and could be exploited for
the application of antibacterial coatings or additives for the food and
beverage industries.
Guangtian Zhou received his B.S. degree in
bioengineering from Shandong Institute of Light Industry, Jinan, China,
in 1982. He was then employed with the Jinan Beer Group as a brewer.
Guangtian studied in Doemens Akademie, Munich, Germany, from August 1987
until November 1988. After graduation, he became chief brewer of the
Jinan Beer Group. Since July 1994, Guangtian has functioned as
professor, tutor of M.S. degree students, and the director of the
China-Germany Beer Technology Center in the School of Food and
Bio-engineering, Shandong Institute of Light Industry, teaching and
researching beer production. At present, he serves as an editor of China Brewing and a council member of Shandong Society for Microbiology.
