Characterization of CLA-producing Butyrivibrio spp. reveals strain-specific variations

Abstract

Conjugated Linoleic Acid (CLA), a fatty acid with high nutraceutical value is produced in rumen by resident bacterial species, especially Butyrivibrio spp. The present study was undertaken to examine the diversity of indigenous Butyrivibrio spp. from rumen liquor of Indian ruminants. The isolates were screened for their CLA production capability at different level of linoleic acid (LA) (0, 200, 400, 600, 800 μg/ml) at different time intervals (0, 2, 4, 6, 12, and 24 h). A total of more than 300 anaerobic cultures were isolated and 31 of them were identified as Butyrivibrio spp. based on morphological, biochemical and molecular characterization. Further, molecular characterization revealed that a large portion (67.7 %) of isolated Butyrivibrio belonged to Butyrivibrio fibrisolvens (B. fibrisolvens) species which is considered to be the most active bacteria amongst the rumen bacteria populace in terms of CLA production. Bacterial isolate VIII (strain 4a) showed highest CLA production ability (140.77 μg/ml) when incubated at 200 μg/ml LA for 2 h, which is 240 % higher than the isolate XXVII, Butyrivibrio proteoclasticus (B. proteoclasticus) showing lowest CLA production (57.28 μg/ml) amongst the screened isolates. It was evident from the observations recorded during the course of experiments that CLA production ability is strain specific and thus did not follow a single pattern. CLA production also varied with time of incubation and concentration of free linoleic acid supplemented in the growth medium. The results of these findings put forward a strain that is high CLA producer and can be further exploited as an additive for enhancing meat and milk quality in ruminants.

Invited review: Role of rumen biohydrogenation intermediates and rumen microbes in diet-induced milk fat depression: An update

“…Some B. fibrisolvens strains further convert this 18:2 isomer to trans-11 18:1, whereas trans-11,cis-15 18:2 is the end product of other strains (Fukuda et al, 2009). This suggests that biohydrogenation of 18:2n-6 and 18:3n-3 is strain specific, as observed by others (Gorissen et al, 2010;Hennessy et al, 2012;Hussain et al, 2016).…”

“…Furthermore, Butyrivibrio spp. was suggested to isomerize 18:2n-6 to cis-9,trans-11 CLA more rapidly than any other bacterial species (Paillard et al, 2007;Shingfield et al, 2012;Hussain et al, 2016), although in most pure culture studies reported in Table 2, this could not be confirmed, as kinetic assessments were lacking. Furthermore, interexperiment comparisons of pure culture studies are challenging, due to diversity in growth media, which might affect the growth and biohydrogenating activity, as some bacteria might face suboptimal conditions.…”

“…For the unclassified taxa, this is impossible. Furthermore, genera, species and strain specificity of PUFA biohydrogenation (Gorissen et al, 2010;Hennessy et al, 2012;Hussain et al, 2016) complicates such studies. Isolation of bacterial strains from the rumen of animals suffering from MFD using a dilution-to-enrichment (or even "extinction") approach with 18:2n-6 or 18:3n-3 as a selection component could potentially reveal other trans-10 producing bacteria.…”

Rumen microbiota and dietary fat: a mutual shaping

“…() and Hussain et al . () showed differences in LA metabolism among several tens of Butyrivibrio isolates, a large number being able to metabolize LA to VA. Slight differences in BH pathways between strains have also been found for ALA metabolism, MDT‐5, A38 and MDT‐10 strains producing trans ‐11, cis ‐13‐CLA, trans ‐11, cis ‐15‐C18:2 or VA, respectively, when incubated with ALA (Fukuda et al .…”

Conjugated linoleic acid producing potential of lactobacilli isolated from goat (AXB) rumen fluid samples

“…This approach can be feasible by adding the ruminant's diet rich in LA and/or by supplementing the microbes directly into the rumen having potential of CLA production which ultimately lead to foods of animal origin with enhanced nutraceutical importance. A number of CLA producing bacteria of the rumen origin including Butyrivibrio fibrisolvens [12], lactic acid bacteria (LAB) namely Lactobacillus acidophilus, Lactococcus lactis subsp. cremoris, L. lactis subsp.…”