title: Radiation-resistant Macrococcus caseolyticus (A) isolated from radiation-processed semidried prawns.
abstract: A radiation-resistant bacterial isolate from gamma-radiation-processed (5 kGy) semidried prawns was identified as a new strain of Macrococcus caseolyticus and was designated as M. caseolyticus (A) on the basis of morphological and biochemical characterization and 16S rRNA sequencing. DNA-DNA hybridization studies with M. caseolyticus DSM 20597(T) further confirmed the isolate as M. caseolyticus. Major fatty acids present in M. caseolyticus (A) were C14:0, C16:1ω11c, and C18:1ω9c, whereas C15:0anteiso, C16:0iso, and C18:0iso were absent. The closest match for the isolate, as per fatty acid methyl ester analysis, was M. caseolyticus DSM 20597(T). However, the similarity index was significantly low (0.112), which indicates that the isolate could be a new strain of M. caseolyticus. The decimal reduction dose (D10) for M. caseolyticus (A), M. caseolyticus JCSC5402, and Staphylococcus aureus MTCC96 was 1.18, 0.607, and 0.19 kGy, respectively. This is the first report on radiation resistance of M. caseolyticus. Macrococcus caseolyticus (A) is more resistant to gamma and UV radiation stress than are M. caseolyticus JCSC5402 and S. aureus MTCC96; however, it is sensitive to heat as well as desiccation stress.
authors.affiliation: Food Technology Division, Bhabha Atomic Research Centre, Tormbay, Mumbai 400 085, India.
authors.forename: Manisha
authors.initials: M
authors.lastname: Karani
authors.forename: Ravindranath
authors.initials: R
authors.lastname: Shashidhar
authors.forename: Aarti
authors.initials: A
authors.lastname: Kakatkar
authors.forename: Raj Kamal
authors.initials: RK
authors.lastname: Gautam
authors.forename: Shibani
authors.initials: S
authors.lastname: Sukhi
authors.forename: Lipika
authors.initials: L
authors.lastname: Pansare-Godambe
authors.forename: Jayant
authors.initials: J
authors.lastname: Bandekar
mesh_terms: D000818:Animals; D003445:Crustacea / Q000382:microbiology* / Q000528:radiation effects; D005227:Fatty Acids / Q000032:analysis / Q000378:metabolism; D005514:Food Irradiation; D005720:Gamma Rays; D010802:Phylogeny; D012758:Shellfish / Q000382:microbiology* / Q000528:radiation effects; D040141:Staphylococcaceae / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D005227:Fatty Acids
keywords: Macrococcus; UV radiation; ionizing radiation; radiation resistant; radiations UV; radiations ionisantes; résistant aux radiations