Significance of Clostridium perfringens in Processed Foods

1977 ◽  
Vol 40 (5) ◽  
pp. 330-332 ◽  
Author(s):  
JOHN T. FRUIN

Clostridium perfringens presents a significant public health hazard to consumers of foods which have undergone improper processing or have been improperly handled at some point before consumption. Factors involved in outbreaks of C. perfringens foodborne illness include contamination of food with either spores or vegetative cells of enterotoxigenic strains of C. perfringens, suitable growth temperature. pH, media, oxidation reduction potential, and adequate incubation time. With proper handling of food items, the risk of C. perfringens foodborne illness outbreaks can be eliminated.

1976 ◽  
Vol 39 (6) ◽  
pp. 421-425 ◽  
Author(s):  
CHRISTINE B. PEARSON ◽  
HOMER W. WALKER

Three strains of Clostridium perfringens were examined for the influence of oxidation-reduction potential on growth and sporulation. The limiting Eh7 for growth was + 350 mv; the cultures slowly died at this Eh. Sporulation occurred at numbers typical for the individual strains as long as growth occurred.


1979 ◽  
Vol 42 (2) ◽  
pp. 144-148 ◽  
Author(s):  
R. R. WILLARDSEN ◽  
F. F. BUSTA ◽  
C. E. ALLEN

Growth of an eight-strain composite of Clostridium perfringens was compared using rolled raw beef strips, raw and autoclaved ground beef and Fluid Thioglycollate medium. The inoculated media were exposed to either static or dynamic temperatures increasing at linear rates. The most rapid growth and shortest lag times were observed in autoclaved ground beef. Generation times in the beef media were directly related to oxidation-reduction potential. Fluid Thioglycollate medium supported the slowest growth even though it presented a favorable Eh.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Adnan Kadić ◽  
Anikó Várnai ◽  
Vincent G. H. Eijsink ◽  
Svein Jarle Horn ◽  
Gunnar Lidén

Abstract Background Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. Results Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation–reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. Conclusion Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation–reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.


Author(s):  
Kamil Gill ◽  
Michal Kups ◽  
Patryk Harasny ◽  
Tomasz Machalowski ◽  
Marta Grabowska ◽  
...  

Since varicocele is so common in infertile men, this study intends to analyse the relationships between varicocele and conventional semen characteristics, sperm nuclear DNA dispersion and oxidation-reduction potential (ORP) in semen. Varicocele-positive and varicocele-negative infertile men (study groups) showed significantly lower standard sperm parameters and higher sperm DNA fragmentation (SDF) and ORP in semen than healthy volunteers and subjects with proven fertility (control groups). A lower proportion of low SDF levels (0–15% SDF) and higher incidence of high SDF levels (>30% SDF), as well as a higher prevalence of high ORP values (>1.37 mV/106 sperm/mL), were found in the study groups vs. the control groups. Moreover, infertile men had significantly lower odds ratios (ORs) for low SDF levels and significantly higher ORs for high SDF levels and high ORP. SDF and ORP were negatively correlated with sperm number, morphology, motility and vitality. Furthermore, a significant positive correlation was found between SDF and ORP. The obtained results suggest that disorders of spermatogenesis may occur in varicocele-related infertility. These abnormalities are manifested not only by reduced standard semen parameters but also by decreased sperm DNA integrity and simultaneously increased oxidative stress in semen.


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