Inhibitory activity of pine needle tannin extracts on some agriculturally resourceful microbes

Abstract

Crude extracts of water and solvent extractable tannin fractions from pine needles were found to contain tannin concentrations of 10.15% and 13.15% tannic acid equivalents respectively. Thin Layer Chromatography revealed the presence of four distinct phenolic compounds, amongst which two were tannic acid like compounds. Both the extracts were found to be inhibitory to several microbes of agricultural importance. Amongst the bacterial strains studied, Azotobacter sp (VL-A2) was able to tolerate upto 1000 ppm of crude tannin concentration without any growth inhibition. While growth of Rhizobium (VL -R1) and Bacillus halodurans (MTCC 7181) was inhibited by crude tannin concentrations of 50 and 100 ppm respectively of both water and solvent extracted tannins. Among the fungal genera, Pleurotus djamor was found to tolerate up to 10000 ppm of crude tannins, while Trichoderma virescens (MTCC 6321) and T. reesii could tolerate up to 3000 ppm of both water extractable and acetone extractable crude tannins without any growth inhibition.

Survival of Salmonella or Escherichia coli O157:H7 during Holding of Manure-Based Compost Mixtures at Sublethal Temperatures as Influenced by the Carbon Amendment

“…Availability of the antimicrobial, however, could be a key factor in its effectiveness. For example, pine needles contain substantial quantities of tannins (15,20) that are known to have antimicrobial properties (1,19), yet Salmonella persisted in compost mixtures containing this carbon amendment (Table 1). A second study was conducted to determine if the carbon amendment affected the fate of Salmonella in dairy cow manure-based compost mixtures to a similar extent as occurred in chicken litter-based compost mixtures.…”

“…Hence, the data from each of the two manure sources were pooled for each of the carbonamended mixtures. Another variable included in this study was the moisture content of compost mixtures amended with wheat straw in which four different moisture contents (20,30,40, and 60%) were prepared. General linear models analysis of these data revealed no differences in the rate of E. coli 0157:H7's inactivation with the different moisture contents at this higher storage temperature (P > 0.05, data not shown); hence, the data were pooled and compared with compost mixtures amended with the other carbon additions and 40% moisture content.…”

Studies on Bio-Pretreatment of Pine Needles for Sustainable Energy thereby Preventing Wild Forest Fires

“…Northup et al 19 reported that they enter the soil affecting soil nutrient dynamics by delaying organic matter decomposition and mineralization. Studies on Trichoderma reesei, a mesophilic and filamentous fungus has gained significant industrial importance over the past decades due to its still yet unmatched hemicellulase producing capacities capable of plant cell wall degradation [20][21][22][23] . The bacterial additive is one of the methods for enhancing biogas production.…”

“…The ability of white-rot fungi to withstand and degrade tannin is well known 27 . Trichoderma virescens and T. reesii were able to tolerate up to 3000 ppm of pine needle crude tannins without any growth inhibition 20 . However, a much smaller group of filamentous fungi has evolved with the ability to break down lignin, the most recalcitrant component of plant cell walls.…”

Root-Nodule Bacteria of Legumes Growing in Semi-Arid African Soils and Other Areas of the World

“…The term "root nodule bacteria, often used to refer to the exclusive presence of rhizobia in nodules, should be redefined with root nodule bacteria capable of acting as a plant growth promoting bacteria/rhizobacteria with specialized ability to colonize the internal tissue of roots of the plant (Selvakumar et al 2007;Palaniappan et al 2010). Beijerinck (1888) was the first to culture the first root-nodule bacteria, which he named Bacillus radicicola (Eckhardt et al 1931).…”