The ligninolytic peroxidases in the genus Pleurotus: divergence in activities, expression, and potential applications

Abstract

Mushrooms of the genus Pleurotus are comprised of cultivated edible ligninolytic fungi with medicinal properties and a wide array of biotechnological and environmental applications. Like other white-rot fungi (WRF), they are able to grow on a variety of lignocellulosic biomass substrates and degrade both natural and anthropogenic aromatic compounds. This is due to the presence of the non-specific oxidative enzymatic systems, which are mainly consisted of lacasses, versatile peroxidases (VPs), and short manganese peroxidases (short-MnPs). Additional, less studied, peroxidase are dye-decolorizing peroxidases (DyPs) and heme-thiolate peroxidases (HTPs). During the past two decades, substantial information has accumulated concerning the biochemistry, structure and function of the Pleurotus ligninolytic peroxidases, which are considered to play a key role in many biodegradation processes. The production of these enzymes is dependent on growth media composition, pH, and temperature as well as the growth phase of the fungus. Mn(2+) concentration differentially affects the expression of the different genes. It also severs as a preferred substrate for these preoxidases. Recently, sequencing of the Pleurotus ostreatus genome was completed, and a comprehensive picture of the ligninolytic peroxidase gene family, consisting of three VPs and six short-MnPs, has been established. Similar enzymes were also discovered and studied in other Pleurotus species. In addition, progress has been made in the development of molecular tools for targeted gene replacement, RNAi-based gene silencing and overexpression of genes of interest. These advances increase the fundamental understanding of the ligninolytic system and provide the opportunity for harnessing the unique attributes of these WRF for applied purposes.

Biotechnological, nutritional and therapeutic uses of Pleurotus spp. (Oyster mushroom) related with its chemical composition: A review on the past decade findings

“…It is a cosmopolitan group of mushrooms with high nutritional value and therapeutic properties, besides a wide array of biotechnological and environmental applications (Knop, Yarden & Hadar, 2015). Usually regarded as oyster mushrooms, these edible basidiomycetes are among the most popular worldwide, as much as they achieved the third position in the production of edible mushrooms, behind the species of the genus Agaricus and Lentinula (Fernandes et al, 2015).…”

“…Extensive research on cultivation techniques (Gregori, Svagelj & Pohleven, 2007;Carvalho, Sales-Campos & Andrade, 2010), chemical composition and nutritional profile (Reis et al, 2012;Atri et al, 2013;Maftoun et al, 2015) has been done in the last ten years, along with a comprehensive account of the biotechnological capabilities of the genus Pleurotus including enzyme production (Inácio et al, 2015a;Knop, Yarden & Hadar, 2015) (Figure 2). More recently, the scientific reports referring to Pleurotus species have also focused on novel approaches for taxonomic issues (Menolli Jr., Breternitz & Capelari, 2014;Maftoun et al 2015), isolation and characterization of new functional compounds, besides the in depth-study of their medicinal properties (Khan & Tania, 2012;Patel, Narain & Singh, 2012;Yahaya, Rahman & Abdulhah, 2014).…”

Limits of Versatility of Versatile Peroxidase

“…VPs are capable of oxidizing Mn 2ϩ via a mechanism similar to that described for MnPs (13). In addition, they directly oxidize low-and high-redox-potential substrates due to two additional active sites via a mechanism similar to that described for LiPs (1). The first is the exposed heme edge that provides VPs the capability to directly oxidize phenols, amines, and small dye compounds in the absence of Mn 2ϩ (14).…”

“…ersatile peroxidases (VPs) from white rot fungi (WRF) such as Pleurotus ostreatus have received much attention in recent years due to their diverse ability to oxidize both low-and highredox-potential compounds, including lignin, in both Mn 2ϩ -mediated and Mn 2ϩ -independent modes of action (1). VPs (EC 1.11.1.16) are ligninolytic enzymes and, together with manganese peroxidases (MnPs) (EC 1.11.1.13), comprise the ligninolytic heme peroxidase gene family of P. ostreatus (2).…”

Insights into the Mechanism of Lignocellulose Degradation by Versatile Peroxidases

“…Structural elements that hold this property reveal a heme porphyrin ring in a central pocket surrounded by two channels for access by hydrogen peroxide, the activator of enzyme complex and for manganese ion. The heme pocket is stabilized by two helical domains with Ca 2+ and proximal and distal basic histidine residues, a feature representative of the class II plant, fungal and bacterial peroxidases 10 . The catalytic cycle of versatile peroxidase for oxidation of low redox potential substrates follows a similar mechanism of oxidation as other constituent members of heme peroxidase family, but stands out in possessing an added ability to utilize manganese as substrate.…”