scholarly journals A novel host-vector system for Butyrivibrio fibrisolvens and its possible use for developing more fibrolytic rumen bacteria

1996 ◽  
Vol 45 (Suppl. 1) ◽  
pp. 342-342
Author(s):  
Y. Kobayashi ◽  
N. Okuda ◽  
M. Wakita ◽  
S. Hoshino
Keyword(s):  
Vector System ◽  
Rumen Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Novel Host

Effects of heavy metals and other trace elements on the fermentative activity of the rumen microflora and growth of functionally important rumen bacteria

1978 ◽  
Vol 24 (3) ◽  
pp. 298-306 ◽  
Author(s):  
C. W. Forsberg
Keyword(s):  
Trace Elements ◽  
Rumen Fluid ◽  
Inhibitory Effect ◽  
Rumen Bacteria ◽  
Inhibitory Effects ◽  
Butyrivibrio Fibrisolvens ◽  
Fermentative Activity ◽  
Rumen Microflora ◽  
High Concentrations

The inhibitory effects of high concentrations of essential and non-essential trace elements were tested on the rumen microflora using the rate of fermentation in vitro as the assay. The elements (and the concentration causing 50% inhibition) in decreasing order of toxicity were Hg2+ (20 μg/ml), Cu2+ (21 μg/ml), Cr6+ (70 μg/ml), Se4+ (73 μg/ml), Ni2+ (160 μg/ml), Cd2+ (175 μg/ml), As3+ (304 μg/ml), and As5+ (1610 μg/ml). The elements tested that were either weak or non-inhibitory at concentrations greater than 400 μg/ml included Zn2+, Cr2+, Fe2+, Mn2+, Pb2+, and Co2+. Methylmercury was as inhibitory as mercuric chloride to the fermentation. When the inhibitory effect of Cd2+ was tested on separated bacterial and protozoal fractions, it was more inhibitory to the bacteria. The inhibitory effects of trace elements were also determined for a number of axenic cultures of rumen bacteria. The bacteria which most frequently exhibited the greatest sensitivity were Bacteroides succinogenes, Ruminococcus albus, Bacteroides amytophilus, and Eubacterium ruminantium. Those often exhibiting intermediate sensitivities included Butyrivibrio fibrisolvens, Selenomonas niminantium, and Megasphera elsdenii, while Streptococcus bovis was very refractory to all elements tested. Rumen fluid provided a modest protective effect for the bacteria.

The effect of condensed tannins fromLotus pedunculatusandLotus corniculatuson the growth of proteolytic rumen bacteria in vitro and their possible mode of action

2001 ◽  
Vol 47 (7) ◽  
pp. 626-633 ◽  
Author(s):  
A L Molan ◽  
G T Attwood ◽  
B R Min ◽  
W C McNabb
Keyword(s):  
Mode Of Action ◽  
Condensed Tannins ◽  
Large Subunit ◽  
Rumen Bacteria ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Bisphosphate Carboxylase ◽  
Butyrivibrio Fibrisolvens ◽  
Significant Difference

Five strains of proteolytic rumen bacteria were treated with condensed tannins (CT) purified from Lotus pedunculatus and Lotus corniculatus to investigate their effect on the growth of these bacteria in vitro. Streptococcus bovis NCFB 2476, Eubacterium sp. C124b, Prevotella bryantii B14, Butyrivibrio fibrisolvens H17c, and Clostridium proteoclasticum B316Twere tested against 200, 400, and 600 µg CT·mL–1extracted from L. pedunculatus and L. corniculatus. In the absence of CT, all bacterial strains showed typical growth and reached maximum optical density (OD) after 6–8 h of incubation in a plant protein medium. Growth of Eubacterium sp., P. bryantii, and B. fibrisolvens was inhibited (P < 0.01–0.001) more by the CT from L. pedunculatus than by the CT from L. corniculatus. All strains continued to grow in the presence of 200 µg·mL–1of the CT from L. pedunculatus, but attained significantly (P < 0.05–0.01) lower maximum OD600values than (minus CT) controls, except for S. bovis. At 400 and 600 µg·mL–1, the addition of CT from L. pedunculatus inhibited (P < 0.05–0.001) the growth of all bacterial strains tested compared with controls. The growth of Eubacterium sp. and P. bryantii was stimulated for the first 4–6 h of incubation (P < 0.001) by 200 µg·mL–1of CT from L. corniculatus, but then declined leading to a significant difference in OD values compared with the controls. At 400 µg·mL–1, the CT from L. corniculatus reduced (P < 0.05–0.01) the growth of all strains except S. bovis, while 600 µg·mL–1inhibited (P < 0.01–0.001) the growth of all strains. To study the mechanism of CT action, the degradation of the large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; Fraction 1 Leaf protein) was followed after bacterial cells or Rubisco were preincubated with CT extracted from L. corniculatus and L. pedunculatus. Both preincubations decreased LSU degradation, but they differed in their response to polyethylene glycol (PEG) addition. Addition of PEG to CT–Rubisco preincubations negated the effects of CT, while PEG addition to CT–bacteria preincubations did not. This implies that the CT–bacterial interaction is stronger than the CT–Rubisco interaction or the interaction is of a different type. Also, L. pedunculatus CT reduced the degradation of the LSU to a greater extent than the CT from L. corniculatus when preincubated with bacteria.Key words: condensed tannins, growth, in vitro, proteolytic rumen bacteria, mode of action, Rubisco.

Genetic manipulation of rumen bacteria: from potential to reality

1996 ◽  
Vol 47 (2) ◽  
pp. 247 ◽  
Author(s):  
K Gregg ◽  
G Allen ◽  
C Beard
Keyword(s):  
Molecular Genetics ◽  
Genetic Manipulation ◽  
Bacterial Species ◽  
Genetic Material ◽  
Rumen Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Prevotella Ruminicola ◽  
The Stability

The development of techniques for manipulating the molecular genetics of bacteria led naturally to suggestions for using this technology to alter rumen function. Despite early difficulties, methods are now available to insert new genetic material into several rumen bacterial species, including Butyrivibrio fibrisolvens, Prevotella ruminicola, and Ruminococcus albus. One strain of B. fibrisolvens has been modified to detoxify a naturally occurring poison that causes major losses of livestock in Australia, Africa, and Central America. The stability of that modified organism has been demonstrated by its recolonization of the rumen and retention of its altered genotype over 5 months in vivo. Many of the persistent doubts about rumen bacterial genetic manipulation and the viability of altered organisms in a competitive environment have been shown to be capable of resolution, and interest in this area of research may be revitalized by these results. Apart from the achievement of specific metabolic improvements, the technology now available will allow extensive characterization of the molecular genetics of rumen bacteria with a precision that was not previously possible.

Sign in / Sign up

Export Citation Format

Share Document