Effect of laser radiation on the growth of <i>Rhodotorula mucilaginosa</i> isolated from rumin fluid of cows in the Nineveh, Iraq

Abstract

Background: The fungi Rhodotorula species are widespread airborne contaminants and are thought to be natural
occupants of human skin, lungs, urine, and feces. Therefore, Rhodotorula mucilaginosa, Rhodotorula minuta, and
Rhodotorula glutinis are three of the most prevalent species.

Aim: This study aims to isolate R. mucilaginosa from the rumen fluid of cows in the province of Mosul and to determine how laser light irradiation affects the growth and morphological traits of these Fungi.

Methods: From the rumen fluid of AL-Restaki and AL-Karadi of cows, the R. mucilaginosa was isolated. Using the
traditional approach and the ID-Yst card system Vitek 2. A semiconductor laser system with a power of 50 mW and a
wavelength of 450 nm was used in the experiment to evaluate the light laser irradiation effects on the culture growth
of R. mucilaginosa directly under two light irradiation conditions of 30 and 60 minutes.

Results: According to traditional methods and the ID-Yst card system Vitek 2, R. mucilaginosa predominated 7/30
(23.3%), and these strains effectively grow on medium sabouraued dextrose agar as evidenced by the carotenoid
pigments that gave their colonies a salmon-pink to coral-red. Compared with a control group where no laser was
used, the impact of light laser irradiation was assessed 24 hours after the irradiation using biomass (dry weight
measuring yeast cell content in suspension) and microscopic analysis using Gram stain. Microscopic examinations
showed the irregular shape of the cells linked to one another. The irradiated subculture of on Sabouraued dextrose agar
and incubation at 37°C for 3 days demonstrated inhibited growth in 4/7 (57.1%) isolates. In addition, there was no
discernible difference vertically at p < 0.05 between the control group and the R. mucilaginosa biomass concentration
under light irradiation circumstances (30 and 60 minutes).

Conclusion: This study proved that R. mucilaginosa is found in the rumen fluid of cows. Also, the isolated R. mucilaginosa
displayed sensitivity to laser irradiation lights, revealing the more significant topographical alterations of the cell  structure that had happened, the irregular shape of the cells, and how they were connected as a result of evolution.