Effect of Ammoniated and/or Basidiomycete White-Rot Fungi Treatment on Rice Straw Proximate Composition, Cell Wall Component, and In Vitro Rumen Fermentation Characteristics

Abstract

Various pretreatments are employed to increase the utilization of rice straw as a ruminant feed ingredient to minimize its negative environmental impact. However, an efficient alternative is still needed. The purpose of this study was to evaluate the ability of ammonia and/or white-rot fungi (Pleurotus ostreatus) to degrade lignin, increase the nutritional value, and enhance the rumen fermentability of rice straw. Rice straw was treated with ammonia and/or basidiomycete white-rot fungi (P. ostreatus) with untreated straw as control under solid-state fermentation employing a completely randomized design. The crude protein increased from 2.05% in the control to 3.47% in ammoniated rice straw, 5.24% in basidiomycete white-rot fungi (P. ostreatus), and 6.58% in ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw. The ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw had the least lignin content (3.76%). Ammoniated-basidiomycete white-rot fungi-treated (P. ostreatus) rice straw had improved in vitro dry matter digestibility (65.52%), total volatile fatty acid (76.56 mM), and total gas production (56.78 mL/g) compared to ammoniated rice straw (56.16%, 67.71 mM, 44.30 mL/g) or basidiomycete white-rot fungi-treated (P. ostreatus) rice straw (61.12%, 75.36 mM, 49.31 mL/g), respectively. The ammoniated-basidiomycete white-rot fungi (P. ostreatus) treatment improved rice straw’s nutritional value, in vitro dry matter digestibility, volatile fatty acids, and gas production.

Novel techniques for the mass production of nutritionally improved, fungus‐treated lignocellulosic biomass for ruminant nutrition

“…47 The high production of propionate by steam and lime pasteurized straw also demonstrates better fermentation of fiber, resulting in a shift in the microbial population or in the metabolic pathways that promote the synthesis of propionate. Increase in the production of VFAs and a decrease in acetate-to-propionate ratio in P. ostreatus treated rice straw is reported by Datsomor et al 48 Considering the findings of previous studies, which showed that wheat straw naturally contains AFB 1 less than 4 ppb, 49 and the findings of Jackson and Pryor, 50 who reported that P. ostreatus can degrade up to 94% of AFB 1 in homogenized whole corn, AFB 1 production during the P. ostreatus treatment was less likely. The concentration of AFB 1 in fungus-treated straw was much lower than the threshold level of AFB 1 in animal feed (20 ppb) recommended by the EU.…”

“…The high production of propionate by steam and lime pasteurized straw also demonstrates better fermentation of fiber, resulting in a shift in the microbial population or in the metabolic pathways that promote the synthesis of propionate. Increase in the production of VFAs and a decrease in acetate‐to‐propionate ratio in P. ostreatus treated rice straw is reported by Datsomor et al 48 …”

Bioconversion of alperujo into an alternative feed for ruminants by pretreatment with live yeasts and/or exogenous fibrolytic enzymes

“…The analysis of the chemical composition of the fresh unfermented alperujo obtained from different industrial of extraction of olive oil using a two-stage centrifugation system in Tunisia is shown in Table 1 . This semi-solid waste is characterized by a high content of lignocellulosic compounds similar to those of cereal straw widely used in rumen feeding, but with a higher content of lignin, protein, and EE (Datsomor et al 2022 ; Sufyan et al 2022 ). The chemical composition of this semi-solid waste was comparable to that found by Marcos et al ( 2019 ) in alperujo from Spain.…”

Emerging technologies of employing algae and microorganisms to promote the return-to-field of crop straws: A mini-review

“…Ammoniation is conducted to generate ammonolysis reaction in crop straw by using ammonia-containing chemicals, such as liquid ammonia, urea, and ammonium bicarbonate ( Yu et al, 2015 ; Doğan and Hayırlı, 2022 ). Through ammoniation, ester bonds between lignin and polysaccharide in crop straw can be damaged, making straw more decomposable in soil ( Datsomor et al, 2022 ). Up to now, although key parameters, including temperature, moisture level, treatment period, and so on, have been optimized, ammonia emission in ammoniation process is still a serious challenge ( Cloete and Kritzinger, 1984 ; Ma et al, 2020c ).…”