Effects of Tween 80 Pretreatment on Dry Matter Disappearance of Rice Straw and Cellulolytic Bacterial Adhesion

Chan Hee Lee,Jae Y Song,Sung Sill Lee,Ha Guyn Sung,Moosa Eslami,Jong K Ha,Se Young Lee

doi:10.5713/ajas.2007.1397

Abstract

An in situ experiment was conducted to find out whether Tween 80 improves rice straw digestion through increased adhesion of major fibrolytic bacteria. Rice straw was sprayed with various levels of Tween 80 non-ionic surfactant or SDS ionic surfactant 24 h before incubation in the rumen of Holstein steers. Dry matter (DM) disappearance and adhesion of F. succinogenes, R. flavefaciens and R. albus on rice straw after in situ incubation were measured by real-time PCR. Application of Tween 80 increased DM disappearance, which was more noticeable at an application level of 1% compared to lower application levels. Application of SDS resulted in an opposite response in DM disappearance with highest reduction in DM disappearance at 1% level. In a subsequent in situ experiment, higher Tween 80 was applied to rice straw in an attempt to find the optimum application level. Tween 80 at 2.5% gave better DM disappearance than 1% with a similar result at 5%. Therefore, an adhesion study was carried out using rice straw treated with 2.5% Tween 80. Our results indicated that Tween 80 reduced adhesion of all three major rumen fibrolytic bacteria to rice straw. Present data clearly show that improved DM disappearance by Tween 80 is not due to increased bacterial adhesion onto substrates.

Highlights

Non-ionic surfactants (NIS) such as Tween 80 have been shown to improve production of ruminant animals (Kamande, 1994; McAllister et al, 2000; Lee et al, 2003; Wang et al, 2003; Kim et al, 2004)
Since the attachment of fibrolytic bacteria is regarded as an obligatory step in fiber degradation (Sung et al, 2007), we aimed to determine whether beneficial effects of Tween 80 on improvement of fiber digestion is due to enhanced microbial attachment on fibrous substrate
Tween80, non-ionic surfactant, at a 1% level (Figure 1A) increased (p

Summary

Introduction

Non-ionic surfactants (NIS) such as Tween 80 have been shown to improve production of ruminant animals (Kamande, 1994; McAllister et al, 2000; Lee et al, 2003; Wang et al, 2003; Kim et al, 2004). Tween 80 has been shown to enhance ruminal fermentation and total tract digestibility (Kim et al, 2004) and to increase DM intake and milk production in cattle (Lee et al, 2003). Wang et al (2003) observed that Tween 80 increased the rate of gas and volatile fatty acid production during in vitro fermentation of corn and orchardgrass silages. Baah et al (2005) indicated that Tween 80 with and without fibrolytic enzyme enhanced in situ disappearance of orchardgrass hay with no influence on total tract digestibility in Holstein cows. Kamande et al (2000) reported that Tween 80 promoted the binding of enzymes to their substrates and increased microbia protease and cellulase activities in vitro, Kim et al (2006) indicated that Tween 80 decreased enzyme adsorption to substrate but enhanced enzyme activity

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