ABSTRACT
Mycorrhizae association is reported to enhance the survivability of the host plant under adverse environmental conditions. The present study aims to explore the mycorrhizal association in the roots of different ecotypes of a threatened medicinal plant, Clerodendrum indicum (L.) O. Kuntze (Verbenaceae), collected from W.B., India, which correlates the degree of root colonization to the nutritional status of the native soil. Ten ecotypes of C. indicum having diverse morphological variations were collected. The mycorrhizae were characterized by both morphological and molecular methods. The nutritional status of the native soils was estimated. The study revealed that all the ecotypes have an association with mycorrhizal forms like hyphae, arbuscules, and vesicles. The molecular analysis showed Glomus intraradices and Rhizophagus irregularis as the associated arbuscular mycorrhizal fungi (AMF). A significant variation in arbuscule and vesicle formation was found growing in the varied nutritional statuses concerning soil parameters. The arbuscule was found negatively correlated with pH, conductivity, and potassium and positively correlated with organic carbon, nitrogen, and phosphorus. The vesicle was found positively correlated with pH, organic carbon, and potassium and negatively correlated with conductivity, nitrogen, and phosphorus. The interaction between conductivity: nitrogen, conductivity: phosphorus, organic-carbon: nitrogen, and pH: conductivity was significant in influencing vesicle formation. However, none of the interactions between parameters was found significant in influencing arbuscule formation. Thus, the study concludes that G. intraradices and R. irregularis are the principle mycorrhizae forming the symbiotic association with the threatened medicinal plant, C. indicum. They form vesicles and arbuscules based on their soil nutritive factors. Therefore, a large-scale propagation through a selective AMF association would help in the conservation of this threatened species from extinction.
Subject(s)
Clerodendrum , Mycorrhizae , Plants, Medicinal , Verbenaceae , Mycorrhizae/genetics , Plant Roots/microbiology , Phosphorus , Soil , Nitrogen , Carbon , PotassiumABSTRACT
Lactococcus spp. are industrially crucial lactic acid bacteria (LAB) used to manufacture lactic acid, pickled vegetables, buttermilk, cheese, and many kinds of delicious dairy foods and drinks. In addition to these, they are also being used as probiotics in specific formulations. However, their uses as probiotics are comparatively less than the other LAB genera. The present communication hypothesizes to validate the probiotic potentiality of two new Lactococcus lactis subsp. lactis strains for their future uses. These native food fermenting strains were characterized for in vitro acid tolerance, tolerance to simulated gastric and pancreatic juices, autoaggregation and co-aggregation, hydrophobicity, haemolytic activity, bile salt deconjugation, cholesterol removal, antimicrobial spectrum, and antibiotic sensitivity. The in vivo live bacterial feeding of these strains for 30 days was done in Swiss albino mice either singly or in combination with prebiotic inulin and evaluated for hypocholesterolemic activity, immune enhancement, and gut colonization efficiency and compared with the commercial probiotic consortia. The study revealed that the strains could survive in human gut bile concentration, gastric pH conditions at pH 2.0, 3.0, and 8.0 for 6 h, had a broad antibacterial spectrum, and cholesterol binding efficacy. The strains could survive with higher colony-forming units (CFU/mL) when amended with sodium caseinate. The strains had autoaggregation ranges from 15 to 25% over 24 h and had a significant co-aggregation with both lactic acid and Gram-positive and Gram-negative bacterial strains related to human illness. The strains also showed solvent and media-specific hydrophobicity against n-hexane and xylene. The live bacterial feeding either singly or in combination with prebiotic inulin resulted in a significant reduction of LDL (low-density lipoprotein), VLDL (very low-density lipoprotein) cholesterol and triglyceride (TG), and a significant increase in HDL (high-density lipoprotein) cholesterol level, and improved gut colonization and gut immunomodulation. The results prove that these non-haemolytic, non-toxic strains had significant health benefits than the commercial probiotics consortium with the recommended prebiotics mix. Thus, these new Lactococcus lactis subsp. lactis strains could be trialled as a new probiotic combination for human and animal feeds.