In situ localization of manganese peroxidase production in mycelial pellets of Phanerochaete chrysosporium

Abstract

The ultrastructure of Phanerochaete chrysosporium hyphae from pellets in submerged liquid cultures was investigated in order to learn more about the interrelation between fungal architecture and manganese peroxidase (MnP) production. At day 2 of cultivation, some subapical regions of hyphae in the outer and middle zones of the pellet initiated differentiation into intercalary thick-walled chlamydospore-like cells of about 10 mm diameter. At the periphery of the cytoplasm of these cells, a large number of mitochondria and Golgi-like vesicles were observed. The sites of MnP production were localized at different stages of cultivation by an immunolabelling procedure. The immunomarker of MnP was mainly concentrated in the chlamydospore-like cells and principally distributed in Golgi-like vesicles located at the periphery of the cytoplasm. The apices of hyphae in the outer layer of the pellets were apparently minor sites of MnP production. Maximal MnP release into the culture supernatant coincided with apparent autolysis of the chlamydospore-like cells. Production of extracellular autolytic chitinase and protease coincided with the disappearance of these structures from the pellets. The chlamydospore-like cells observed in the mycelial pellets of P. chrysosporium could be metabolically active entities operating as an enzyme reservoir, delivering their content into the surrounding medium possibly by an enzyme-mediated autolytic process.

Impact of pellet size on growth and lignin peroxidase activity of Phanerochaete chrysosporium

“…It can be concluded that LiP seems to be excreted on the pellet surface where probably most of the hyphal tips are present. This datum is in agreement with previous works using P. chrysosporium where it was speculated that peroxidases are excreted through the apex of secondary growing hyphae (Moukha et al 1993) or by autolysis of chlamydospore-like cells present in outer or middle zones of the pellets (Jimé nez- Tobon et al 2003).…”

Regulation of Autolysis in Aspergillus nidulans

“…The emerging regulatory elements of autolysis provide us with good opportunities to control and manipulate this process for several practical proposes. In the fermentation industry, induction of autolysis can accelerate the release of certain intracellular metabolites [1,7] and enhance the production of numerous industrially important hydrolases including proteinases, chitinases, and glucanases [1] and other enzymes [8]. Inhibition of autolysis can also help us to lengthen the idiophase of industrial cultivations, can maintain pelleted cell morphology as well as can hinder or even block proteinase production and, hence, proteolytic degradation of valuable protein products [1,4].…”

Relationship between cultivation mode of white rot fungi and their efficiency for olive oil mill wastewaters treatment

“…Intermediate values would be useful to determine in order to establish if any correlation exists between laccase activity and phenolics degradation. It was for example shown that ligninolytic enzymes may be sensitive to proteases produced by different WRF strains during their growth cycle (Jimenez-Tobon et al 2003). Although, apparently not detected in the present investigation (not illustrated), the role of other enzymes, including Lignin peroxidase, Manganese peroxidase (Kondo et al 1994;Belinky et al 2003;Songulashvili et al 2007) and cellobiose dehydrogenase should be also evaluated in more details.…”