Atrazine detoxification by intracellular crude enzyme extracts derived from epiphytic root bacteria associated with emergent hydrophytes.

The present study demonstrated atrazine detoxification by intracellular crude enzyme extracts of Pseudomonas spp. strains ACB and TLB. Indigenous bacterial protein-based remediation techniques could be an alternative to bioaugmentation which pose multiple challenges when applied to the field. Intracellular enzymes were extracted from strains ACB and TLB and their degradation potential of 10 mg L-1 was determined using Gas Chromatography; further, enzyme extracts were subjected to protein profiling studies. In span of 6 h, enzyme extracts of strain ACB showed maximum degradation at 30 °C and 40 °C (71%) and enzyme extracts of strain TLB showed maximum degradation at 40 °C (48%). Atrazine degradation by enzyme extracts of strain ACB showed maximum degradation at pH 7 (71%) and pH 6 (69%) in 6 h. Similarly, enzyme extracts of strain TLB showed maximal degradation at pH 6 (46%) in 6 h. The present study demonstrated, for the first time, efficient atrazine remediation by intracellular crude enzyme extracts from epiphytic root bacteria at a range of temperature and pH conditions. Protein profiling studies indicated that atrazine induced expression of CoA ester lyase and alkyl hydroperoxide reductase in the strains ACB and TLB respectively. Expressions of these proteins have never been associated with atrazine exposure.

Mycorrhizal inoculation impact on Acorus calamus L. - An ethnomedicinal plant of western Himalaya and its in silico studies for anti-inflammatory potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Different plants are used for the treatment of various ailments and Acorus calamus L. is one such plant found in Western Himalaya. Rhizome of this plants has ethnomedicinal significance, as its rhizome is used for curing fever, pain and inflammation. An attempt has been made to alter the phytochemicals and increase its antioxidant property in a sustainable way with the help of mycorrhizal inoculation. AIM OF THE STUDY: Study of mycorrhizal (Funneliformis mosseae) impact on the biological activities and phytochemical profile of A. calamus L. rhizome and in silico studies of phytochemicals for their anti-inflammatory property. MATERIALS AND METHODS: F. mosseae was mass multiplied by single spore culture and then A. calamus rhizomes were inoculated with it. Antioxidant potential of rhizome extract was observed by DPPH and FRAP assays and the phytochemical profiling was done with GC-MS analysis. For observing antimicrobial activity disc diffusion method was employed. Dominant phytochemicals α-asarone and monolinolein TMS were chosen for molecular docking studies against four receptors (4COX, 2AZ5, 5I1B, 1ALU). RESULTS: There was increase in antioxidant activity of rhizome extract after mycorrhizal inoculation. However, no change in antimicrobial activity was observed in the plant after mycorrhizal inoculation. The comparison in phytochemicals was observed by GC-MS analysis which showed qualitative and quantitative variation in biochemical content in plants. The phytochemical, α-asarone and monolinolein TMS showed highest docking score and least binding energy against 1ALU and 4COX respectively for anti-inflammatory activity. CONCLUSION: Medicinal plants are potential source of antioxidants which can be increased by mycorrhizal inoculation without addition of chemical fertilizers and also results in altering the phytochemical composition.

[Effects of Mycorrhizal Fungi on Nitrification and Denitrification in the Rhizospheric Soil of Aquatic Plants and Its Microbial Mechanism].

To investigate the effect of mycorrhizal fungi inoculation on nitrification-denitrification in the rhizospheric soil of aquatic plants, Cyperus alternifolius and Acorus tatarinowii were inoculated with the strain MF-MD obtained from local soil. Uninoculated plants served as the control group. The plants were cultivated for 3 months under nitrogen eutrophication in water, and then the nitrification and denitrification activities in the rhizospheric soil were determined. The results showed that inoculation with MF-MD promoted nitrification in the rhizospheric soil of both plants. However, MF-MD inoculation promoted denitrification in the rhizospheric soil of Cyperus alternifolius but inhibited denitrification in the rhizospheric soil of Acorus tatarinowii. The mechanism of soil nitrification-denitrification activity was analyzed by measuring the changes in the community structure of nitrifying bacteria and denitrifying bacteria in the microbial biomass of the rhizospheric soil. It was found that the rhizospheric soil microbial biomass (SMB) of the experimental group was higher than that of the control group and that the changes in the microbial community structure related to soil nitrification and denitrification differed between groups. This study contributes to an understanding of how mycorrhizal fungi combined with aquatic plants can remove N content in eutrophic water.

Phytotoxicity and oxidative stress of perfluorooctanesulfonate to two riparian plants: Acorus calamus and Phragmites communis.

Despite previous efforts and the rapid progress on elucidating the impact of perfluorooctanesulfonate (PFOS) on the environment, its effects on riparian plants, a key component of aquatic ecosystems, are still poorly understood. A 48-day hydroponic experiment was carried out on two typical riparian species (Acorus calamus and Phragmites communis) to examine the toxic effects of PFOS on these plants. The results showed that, at high concentration (more than 10 mg L-1), PFOS could prevent chlorophyll accumulation (reduced by 13.7-22.2% at 10 mg L-1 PFOS and 22.4-30.0% at 50 mg L-1 PFOS for 48 days) and soluble protein synthesis (reduced by 2.3-9.0% at 10 mg L-1 PFOS and 10.6-26.8% at 50 mg L-1 PFOS for 48 days). Contrastingly, less than 1 mg L-1 of PFOS could induce chlorophyll accumulation (increased by 18.6% in A. calamus roots, 11.3% in A. calamus leaves, and 13.6% in P. communis roots at 1 mg L-1 PFOS for 3 days) and soluble protein synthesis (increased by 6.1% in A. calamus roots, 18.4% in A. calamus leaves, 9.7% in P. communis roots, 23.4% in P. communis stems, and 24.0% in P. communis leaves, at 1 mg L-1 PFOS for 6 days). In addition, PFOS led to oxidative stress, as revealed by the elevated concentrations of malonaldehyde and hydrogen peroxide, and reduced the activities of antioxidant enzymes such as superoxide dismutase (reduced by 10.3% in P. communis stems at 50 mg L-1 PFOS for 48 days), catalase (reduced by 20.6-50.3% in test species at 50 mg L-1 PFOS for 48 days), and peroxidase (reduced by 24.9-37.7% in test species at 50 mg L-1 PFOS for 48 days). The biomarkers of both plants changed rapidly in the first half of the experiment (0-24 days) and stabilized in the second half of the experiment (24-48 days). The risk and related factors of PFOS on riparian plants were evaluated by using these biomarkers. Experiments showed that P. communis was more resistant to low concentration (<10 mg L-1) of PFOS than A. calamus.

Assessing the Bacterial Community Structure in the Rhizoplane of Wetland Plants.

Plant-microorganism interaction in the rhizosphere is important for nutrient cycling, carbon sequestration in natural ecosystems, contaminant elimination and ecosystem functioning. Abundance of microbial communities and variation in species composition can be an imperative determinant of phytoremediation capability. In the present study we have assessed the bacterial community structure in the rhizoplane of wetland plants, Acorus calamus, Typha latifolia, and Phragmites karka using Terminal restriction fragment length polymorphism technique. The most dominant phylum, in the plants under study, was phylum Firmicutes, followed by Proteobacteria and Actinobacteria. Bacterial groups belonging to phylum Chloroflexi, Acidobacteria, Deferribacteres and Thermotogae also showed their presence in P. karka and T. latifolia but were absent in A. calamus. Diversity indices of bacterial community were assessed. The results of this study show the presence of bacterial phyla which play an important role in bioremediation of contaminants. Thus these plants can be used as potential candidates of phytoremediation.

Phenylisotertronic acids from the TCM endophytic fungus Phyllosticta sp.

Four new phenylisotertronic acids (1a/1b, 2a, and 3a) were isolated from a TCM endophytic fungal strain Phyllosticta sp. J13-2-12Y obtained from the leaves of Acorus tatarinowii, along with two known ones (2b and 3b). Compounds 1-3 all existed as mixtures of enantiomers, and their corresponding optically pure enantiomers were successfully isolated by chiral HPLC. The structures of isolated compounds were determined by comprehensive spectroscopic analyses and X-ray diffraction. Their absolute configurations were determined by ECD experiments and quantum chemical calculations. In addition, the antimicrobial activities and the cytotoxicities of these three pairs of optically pure enantiomers (1a/1b, 2a/2b, and 3a/3b) had been evaluated.

Atrazine degradation by aerobic microorganisms isolated from the rhizosphere of sweet flag (Acorus calamus L.).

In presented study the capability of microorganisms isolated from the rhizosphere of sweet flag (Acorus calamus) to the atrazine degradation was assessed. Following isolation of the microorganisms counts of psychrophilic bacteria, mesophilic bacteria and fungi were determined. Isolated microorganisms were screened in terms of their ability to decompose a triazine herbicide, atrazine. Our results demonstrate that within the rhizosphere of sweet flag there were 3.8x10(7) cfu of psychrophilic bacteria, 1.8x10(7) cfu of mesophilic bacteria, and 6x10(5) cfu of fungi per 1 g of dry root mass. These microorganisms were represented by more than 20 different strains, and at the first step these strains were grown for 5 days in the presence of atrazine at a concentration of 5 mg/l. In terms of the effect of this trial culture, the bacteria reduced the level of atrazine by an average of about 2-20%, but the average level of reduction by fungi was in the range 18-60%. The most active strains involved in atrazine reduction were then selected and identified. These strains were classified as Stenotrophomonas maltophilia, Bacillus licheniformis, Bacillus megaterium, Rahnella aquatilis (three strains), Umbelopsis isabellina, Volutella ciliata and Botrytis cinerea. Culturing of the microorganisms for a longer time resulted in high atrazine degradation level. The highest degradation level was observed at atrazine concentrations of 5 mg/l for S. maltophilia (83.5% after 15 days of culture) and for Botrytis sp. (82% after 21 days of culture). Our results indicate that microorganisms of the sweet flag rhizosphere can play an important role in the bioremediation of atrazine-contaminated sites.