Importance of bacteriophages in fermentation processes

Abstract

Any bacterial strain can be infected by virulent phages or harbour one or more prophages. Therefore, bacteria-phage interactions are to be regarded as fundamental properties of bacteria. In current industrial fermentation processes phages can be advantageously employed for the identification of bacterial production strains (phage typing). In some cases phages are involved in the production of enzymes and special substances. The fundamental importance of phages in any technical fermentation process, however, is based on the peculiarities of their obligately parasitic life cycle. The propagation of phages in fermentation processes can cause complete (or a t least partial) lysis of the production strains and, consequently, serious disturbances in the production process and considerable economic losses. The phage problem in the fermentation industry has not yet been completely solved. For the protection of technical processes against virulent phages five measures are discussed: phage-protected sterile fermentation, employment. of alternative cultures, employment of phage-resistant mutants. employment of phage inhibitors, and employment of immobilized bacterial cells. The problem of the protection of bacterial production strains from prophage induction is more difficult and practically unsolved. Two possibilities to minimize the process risk due to temperate phages, the elimination of inducing factors during the fermentation process, and the selection of production strains which are difficult to induce, are discussed.

A century of bacteriophage research and applications: impacts on biotechnology, health, ecology and the economy!

“…Originally a range of antiphage chemical agents have been used to prevent or limit phage accumulation and loss of product yield . Spontaneous mutation to multi‐phage resistance has been successfully used to protect the vancomycin fermentation process with Amycolatopsis orientalis .…”

“…55,94,234,235 Originally a range of antiphage chemical agents have been used to prevent or limit phage accumulation and loss of product yield. [236][237][238] Spontaneous mutation to multi-phage resistance has been successfully used to protect the vancomycin fermentation process with Amycolatopsis orientalis. 239,240 Phage-resistant lactic bacteria production strains 241 and spoilage or pathogenic bacterial strains, such as Listeria monocytogenes 242 , important for the food sector have been studied and developed via classical strain improvement approaches based on chemical or UV-based random mutagenesis and subsequent screening.…”

Isolation and Characterization of Two Bacteriophages Infecting Kosakonia sacchari Bacterium Causing Potato Soft Rot Disease

“…Our results are in agreement with [32] who stated that the phage optimum activity should be at neutral pH values. This is attributed to the adsorption of the phage on the host bacterial cell which is affected by pH value, due to charge alteration of protein capsid [33].…”

“…Bacteriophages infectivity is affected by temperature and pH, as those factors cause lipid dissolving, DNA and protein denaturation, leading to phage structure damage [33].…”

Archaeal Viruses, Not Archaeal Phages: An Archaeological Dig

“…Note in particular the diversity as well as, even over the last decade, an apparently ongoing lack of consensus. References for first use, again to the best of our knowledge, are as follows: Bacteriophage (and Phage) [11], Halophage [12], Archaebacterial phage [13], Virus [13] (see, however, also [14]), Archaebacterial virus [15], Archaebacteriophage [16], Archaeobacteriophage [17], Archaeal phage [18], Archaeophage [19], Archaeal virus [20], Archaebacterial bacteriophage [21], Archaea virus [22], Archaevirus [23], Archaephage [24], Archaeavirus [25], Archael virus [26] (also found as a typo in a 1999 publication [27]), Archeal virus [28], Archeophage [29], Archaeovirus [30, 31], Archeovirus [32], Archaeon virus [33], Archae virus [34], and Archaean virus [35]. …”