Importance of the ammonia assimilation by Penicillium purpurogenum in amino derivative Monascus pigment, PP-V, production

Teppei Arai,Kasumi Koganei,Sara Umemura,Takafumi Kasumi,Ryo Kojima,Jun Kato,Jun Ogihara

doi:10.1186/2191-0855-3-19

Abstract

A fungal strain, Penicillium purpurogenum IAM 15392, produced the azaphilone Monascus pigment homolog when cultured in a medium composed of soluble starch, ammonium nitrate, yeast extract, and citrate buffer, pH 5.0. One of the typical features of violet pigment PP-V [(10Z)-12- carboxyl-monascorubramine] is that pyranoid oxygen is replaced with nitrogen. In this study, we found that glutamine synthetase (glnB) and glutamate dehydrogenase (gdh1) genes were expressed in the culture conditions conducive to PP-V production. Gln and Glu both support PP-V biosynthesis, but PP-V biosynthesis was much more efficient with Gln. We determined that synthesis of Gln by glutamine synthetase from ammonium is important for PP-V production.

Highlights

Since ancient times, Monascus spp. have been used as starter cultures in the brewing of red rice wine, and Monascus pigments have been used as a natural food colorant in East Asia (Juzlova et al 1996; Dufosse 2006)
The features of pigment production by P. purpurogenum IAM15392 include the production of PP-V, an amino derivative of the PP-O Monascus pigment homolog, when cultured in a medium supplemented with ammonium nitrate (Ogihara et al 2000)
Expression of glutamine synthetase (GS) and glutamate dehydrogenase (Gdh) genes Expression of GS and Gdh genes showed that glnB and gdh1, respectively, were expressed in PP-V production condition (Figure 1)

Summary

Introduction

Monascus spp. have been used as starter cultures in the brewing of red rice wine, and Monascus pigments have been used as a natural food colorant in East Asia (Juzlova et al 1996; Dufosse 2006). Penicillium purpurogenum IAM 15392 has been found to produce Monascus pigment homologs in culture with a specific medium (Ogihara et al 2000; Ogihara et al 2001; Ogihara and Oishi 2002). This strain does not produce citrinin, making P. purpurogenum IAM15392 a potentially valuable commercial source of natural food colorant. The features of pigment production by P. purpurogenum IAM15392 include the production of PP-V, an amino derivative of the PP-O Monascus pigment homolog, when cultured in a medium supplemented with ammonium nitrate (Ogihara et al 2000). We discuss how GS and Gdh contribute to ammonium assimilation and PP-V production

Materials and methods

Results

Discussion