Effect of insulin on in vitro fermentation activity of microrganism community of rumen ciliate culture

Abstract

The influence of insulin (17.4 nmol l-1) on total gas and methane production, the concentration of total and individual fatty acids and dry matter degradability was investigated in the rumen ciliate culture of Entodinium caudatum. The experimental groups consisted of control group (without insulin) and two groups with insulin application--single shot and long-term application (over 30 days). Fermentation activity of each experimental group was observed on two subgroups: whole protozoan culture (protozoa plus bacteria) and bacterial fraction (bacteria without protozoa). Long-term application of insulin significantly increased methane production and DM degradability in the whole protozoan culture. Total VFA concentration was significantly increased by long-term as well as single-dose application of insulin (by 255% and 158%, respectively). The growth of the protozoa was not influenced by insulin treatments. It can be concluded that the fermentation activity of the community of the rumen ciliate Entodinium caudatum culture was marked stimulated by application of insulin.

Effects of wortmannin, sodium nitroprusside, insulin, genistein, and guanosine triphosphate on chemotaxis and cell growth of Entodinium caudatum, Epidinium caudatum, and mixed ruminal protozoa

“…In panel B, for 0.2 μM wortmannin, all contrasts were P > 0.10; for 2.0 μM wortmannin, the quadratic effect of insulin concentration was P = 0.03 (other contrasts, P > 0.10). The pooled SE was 0.12. production by 158% but did not affect growth (Kisidayová and Varadyova, 2005). In that study, however, the transfer interval was longer than ours, and increasing time since last transfer can limit growth regardless of increasing substrate supply (Dehority, 2004).…”

“…caudatum cultures with 0 (control), 0.20, and 2.0 μM wortmannin for 30 min, after which cultures were fed simultaneously with administration of bovine insulin (>27 USP units/mg; Sigma-Aldrich, St. Louis, MO) to provide final concentrations of 0, 0.10, 0.50, and 2.5 μM. Insulin concentrations were based on a range from studies with Tetrahymena (Christopher and Sundermann, 1992) and rumen ciliates (Kisidayová and Varadyova, 2005). After insulin addition, triplicate samples of 1.5 mL were taken at 0 and 24 h, placed in 2.0-mL microcentrifuge tubes, preserved with formalin, and stained using brilliant green dye for counting.…”

“…This ciliate can even be chemoattracted to insulin (Leick et al, 2001). Ruminal ciliates are potentially stimulated by insulin (Kisidayová and Varadyova, 2005) but have not been assessed for responses to pharmacological agents. Wortmannin is a hydrophobic fungal metabolite that blocks numerous insulin-stimulated responses in human and mammalian cell types (Cho and Park, 2008).…”

Some Aspects of the Physiology of the Nyctotherus velox, a Commensal Ciliated Protozoon Taken from the Hindgut of the Tropical Millipede Archispirostreptus gigas

“…The in vitro gas technique was used to measure the fermentation activity of the microorganism community of Nyctotherus culture [ 31 ]. The in vitro dry matter digestibility (IVDMD), gas volume, methane, ammonium nitrogen, short-chain fatty acids (SCFA), and the number of ciliates after 96 h of fermentations were measured in 50 mL graduated gas-tight glass syringes at 30 °C under anaerobic conditions.…”

Insulin at a unicellular eukaryote level

“…The cell division of Toxoplasma gondii and other protozoa was stimulated by high concentration of insulin (Lawrence, ; Zhu et al, ). Long‐lasting application of insulin increased methane production in Entodynium caudatum rumen culture (Kisidayova and Váradyova, ). Autogamy induction by insulin was also observed in Paramecium primaurelia (Prajer, ).…”