Abstract Arginase plays an imperative role in the cell growth and proliferation of healthy cells under normal physiological conditions. Recently arginase has gained the sight of many researchers as it has emerged as a potential candidate for auxotrophic cancer treatment. Through one variable at a time approach (OVAT), 4-fold enhanced arginase production was observed compared to unoptimized cultural conditions. The highest arginase production (2 U/mL) was achieved when a 1% 10 h old inoculum was used to carry out submerged fermentation for 24 h. Further additional supplementation of media with arginine (15 mM), sucrose (1%), yeast extract (0.3%) and pH (6) also resulted in improved arginase production. Further optimization of cultural conditions by response surface methodology (3.3 U/mL) resulted in 6.6-fold improved arginase yield compared to unoptimized physiochemical cultural conditions. The present work is the first report regarding optimization of arginase production by Lactobacillus acidophilus by OVAT and the statistical approach using central composite design under submerged conditions. This study can further be extended to explore the anti-carcinoma properties of arginase produced by Lactobacillus, followed by its scaling up.

ABSTRACT Collision tumors have been reported in various organs like the gastrointestinal tract, lung, skin, adrenals, central nervous system, lymph nodes, uterus, but are rarely seen in the ovary. Collision tumors are two histologically distinct neoplasms in the same organ without any intermixture between them. Here we present a case of a collision tumor of the ovary represented by a mucinous cystadenoma and teratoma. It is imperative for a surgical pathologist to correctly diagnose the collision tumor components and differentiate them from mixed tumors as it will dictate the appropriate treatment based on the individual biological aggressiveness of each component.