amino acids and nucleotides, bioconversion of steroids, degradation of hydrocarbons, cheese aging, and production of enzymes. Some species produce metabolites similar to antibiotics: bacteriocins of the corynecin-linocin type, antitumor agents, etc. One of the most studied species is C. glutamicum, whose name refers to its capacity to produce glutamic acid in aerobic conditions. L-Lysine production is specific to C. glutamicum in which core metabolic enzymes are manipulated through genetic engineering to drive metabolic flux towards the production of NADPH from the pentose phosphate pathway, and L-4-aspartyl phosphate, the commitment step to the synthesis of L-lysine, lysC, dapA, dapC, and dapF. These enzymes are up-regulated in industry through genetic engineering to ensure adequate amounts of lysine precursors are produced to increase metabolic flux. Unwanted side reactions such as threonine and asparagine production can occur if a buildup of intermediates occurs, so scientists have developed mutant strains of C. glutamicum through PCR engineering and chemical knockouts to ensure production of side-reaction enzymes are limited. Many genetic manipulations conducted in industry are by traditional cross-over methods or inhibition of transcriptional activators. Expression of functionally active human epidermal growth factor has been brought about in C. glutamicum, thus demonstrating a potential for industrial-scale production of human proteins. Expressed proteins can be targeted for secretion through either the general secretory pathway or the twin-arginine translocation pathway. Unlike gram-negative bacteria, the gram-positive Corynebacterium species lack lipopolysaccharides that function as antigenic endotoxins in humans. Species Corynebacterium comprises the following species: C. accolens Neubauer et al. 1991 C. afermentans Riegel et al. 1993 C. alimapuense Claverias et al. 2019 "C. alkanolyticum" Lee and Reichenbach 2006 C. ammoniagenes (Cooke and Keith 1927) Collins 1987 C. amycolatum Collins et al. 1988 C. anserum Liu et al. 2021 C. appendicis Yassin et al. 2002 C. aquatimens Aravena-Román et al. 2012 C. aquilae Fernández-Garayzábal et al. 2003 C. argentoratense Riegel et al. 1995 "C. asperum" De Briel et al. 1992 C. atrinae Kim et al. 2015 C. atypicum Hall et al. 2003 C. aurimucosum Yassin et al. 2002 C. auris Funke et al. 1995 C. auriscanis Collins et al. 2000 C. belfantii Dazas et al. 2018 C. beticola Abdou 1969 (Approved Lists 1980) "C. bouchesdurhonense" Ndongo et al. 2017 "C. bouchesdurhonense" Lo et al. 2019 C. bovis Bergey et al. 1923 (Approved Lists 1980) C. callunae (Lee and Good 1963) Yamada and Komagata 1972 (Approved Lists 1980) C. camporealensis Fernández-Garayzábal et al.