Abstract

ABSTRACTAspergillus oryzae is a safe filamentous fungus widely used in the food, medicine, and feed industries, but there is currently not enough research on the light response of A. oryzae. In this study, 12 different light conditions were set and A. oryzae GDMCC 3.31 was continuously irradiated for 72 h to investigate the effect of light on mycelial growth and conidium production. Specifically, each light condition was the combination of one light wavelength (475, 520, or 630 nm) and one light intensity (20, 40, 60, or 80 μmol photon m−2 s−1). The results show that mycelium growth was inhibited significantly by green light (wavelength of 520 nm and intensities of 20 and 60 μmol photon m−2 s−1) and blue light (wavelength of 475 nm and intensity of 80 μmol photon m−2 s−1). The production of conidia was suppressed only by blue light (wavelength of 475 nm and intensities of 40, 60, and 80 μmol photon m−2 s−1), and those levels of inhibition increased when the intensity of blue light increased. When the strain was irradiated by blue light (80 μmol photon m−2 s−1), the number of conidia was 57.4% less than that of the darkness group. However, within our set range of light intensities, A. oryzae GDMCC 3.31 was insensitive to red light (wavelength of 630 nm) in terms of mycelium growth and conidium production. Moreover, interaction effects between light wavelength and intensity were found to exist in terms of colony diameter and the number of conidia. This research investigated the light response of A. oryzae, which may provide a new method to regulate mixed strains in fermented foods by light.IMPORTANCE Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism. However, research methods for the light response of A. oryzae remain in the use of white light sources. In this study, we first demonstrated that A. oryzae GDMCC 3.31 was sensitive to light wavelength and intensity. We have observed that blue light inhibited its growth and sporulation and the inhibitory effect increased with intensity. This research not only adds new content to the study of the photoreaction of Aspergillus but also brings new possibilities for the use of light to regulate mixed strains and ultimately improve the flavor quality of fermented foods.

Highlights

  • IMPORTANCE Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism

  • Our results showed that blue light at a certain intensity inhibits the mycelium growth and conidium production of A. oryzae GDMCC 3.31, while GDMCC 3.31 is insensitive to red light

  • Those results demonstrated that the mycelial growth of the A. oryzae GDMCC 3.31 was inhibited by green light and blue light

Read more

Summary

Introduction

IMPORTANCE Studies on the monochromatic light response of Aspergillus nidulans and Neurospora crassa have gone deep into the molecular mechanism. Some researchers have conducted preliminary studies on the light response of the growth and reproduction of A. oryzae It was first found in 2007 that in RIB40, a standard strain of Aspergillus oryzae, conidiation was repressed by white light at an intensity of 94.2 mmol photon m22 s21 and red light at an intensity of 75.5 mmol photon m22 s21, while one industrially applied strain showed no conserved result [17]. We used two-way analysis of variance (ANOVA) to analyze the effect of interaction between light wavelength and intensity on these responses This lays the seeds for future research to find out the photoreceptor and verify its photoresponse range

Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call