Metabolite profiling of plant growth promoting cyanobacteria-Anabaena laxa and Calothrix elenkinii, using untargeted metabolomics.

The metabolite profiles of two plant growth promoting cyanobacteria-Anabaena laxa and Calothrix elenkinii, which serve as promising biofertilizers, and biocontrol agents were generated to investigate their agriculturally beneficial activities. Preliminary biochemical analyses, in terms of total chlorophyll, total proteins, and IAA were highest at 14 days after inoculation (DAI). In A. laxa 20-25% higher values of reducing sugars, than C. elenkinii at both 14 and 21 DAI were recorded. Carbon and nitrogen assimilating enzyme activities-phosphoenol pyruvate carboxylase (PEPC), carbonic anhydrase (CA), and glutamine synthetase (GS) were highest at 14 DAI, albeit, nitrate reductase (NR) activity was higher by 0.73-0.84-fold at 21 DAI. Untargeted GC-MS (Gas chromatography-Mass spectrometric) analysis of metabolite profiles of 21d-old cyanobacterial cultures and characterization using NIST mass spectral library illustrated that A. laxa recorded highest number of metabolite hits in three chemical classes namely amino acid and peptides, nucleotides, nucleosides and analogues, besides other organic compounds. Based on the pathway analysis of identified metabolites, both A. laxa, and C. elenkinii were enriched in metabolites involved in aminoacyl-tRNA biosynthesis, and amino acid metabolism pathways, particularly lactose and glutamic acid, which are important players in plant-microbe interactions. Correlation-based metabolite network illustrated distinct and significant differences in the metabolic machinery of A. laxa and C. elenkinii, highlighting their novel identity and enrichment in C-N rich metabolites, as factors underlying their plant growth and soil fertility enhancing attributes, which make them valuable as inoculants. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03902-7.

Elevated CO2 along with inoculation of cyanobacterial biofilm or its partners differentially modulates C-N metabolism and quality of tomato beneficially.

Diazotrophic cyanobacteria are known to influence nutrient availability in soil, however, their benefits under elevated CO2 environment, particularly on fruit quality attributes, is a less investigated aspect. Laboratory developed cyanobacterium-fungal biofilm (An-Tr), composed of Anabaena torulosa (An) as the matrix with the partner as Trichoderma viride (Tr), along with the individual partners were evaluated under ambient (aCO2-400 ± 50 ppm) and elevated (eCO2-700 ± 50 ppm) conditions, with and without tomato plants. An-Tr inoculation exhibited distinct and significantly higher values for most of the soil microbiological parameters, plant growth attributes and antioxidant/defense enzyme activities measured at 30 and 60 DAI (days after inoculation). Significant enhancement in soil nutrient availability, leaf chlorophyll, with 45-50% increase in the enzyme activities related to carbon and nitrogen assimilation, higher yields and better-quality parameters of tomato, with An-Tr biofilm or An inoculation, were recorded, particularly under eCO2 conditions. The fruits from An-Tr treatments under eCO2 exhibited a higher titrable acidity, along with more ascorbic acid, carotenoids and lycopene content, highlighting the superiority of this inoculant. Multivariate analyses revealed significant (p ≤ 0.05) interactions among cultures, DAI, and CO2 levels, illustrating that cyanobacterial inoculation can be advocated as a strategy to gainfully sequester eCO2. Significant improvement in yield and fruit quality along with 50% N savings, further attest to the promise of cyanobacterial inoculants for tomato crop in the climate change scenario.

Untargeted GC-MS reveals differential regulation of metabolic pathways in cyanobacterium Anabaena and its biofilms with Trichoderma viride and Providencia sp.

Cyanobacteria and their biofilms are used as biofertilizing options to improve plant growth, soil fertility, and grain quality in various crops, however, the nature of metabolites involved in such interactions is less explored. The present investigation compared the metabolite profiles of cyanobacterial biofilms: Anabaena torulosa- Trichoderma viride (An-Tr) and A. torulosa- Providencia sp. (An-PW5) against the individual culture of A. torulosa (An) using untargeted gas chromatography-mass spectroscopy. Metabolites were identified using the NIST mass spectral library and the relative peak area of cultures analysed, after normalization with an internal standard, ribitol. An-Tr biofilm recorded approximately 66.85% sugars, with increased quantity and numbers of sugars and their conjugates, which included maltose, lactose, and d-mannitol, but decreased amino acids concentrations, attributable to the effect of Tr as partner. Heat map and cluster analysis illustrated that An-Tr biofilm possessed a unique cluster of metabolites. Partial least square-discriminate analysis (PLS-DA) and pathway analyses showed distinct modulation in terms of metabolites and underlying biochemical routes in the biofilms, with both the partners- PW5 and Tr eliciting a marked influence on the metabolite profiles of An, leading to novel cyanobacterial biofilms. In the An-PW5 biofilm, the ratios of sugars, lactose, mannitol, maltose, mannose, and amino acids serine, ornithine, leucine and 5­hydroxy indole acetic acid were significantly higher than An culture. Such metabolites are known to play an important role as chemoattractants, facilitating robust plant -microbe interactions. This represents a first-time study on the metabolite profiles of cyanobacterial biofilms, which provides valuable information related to their significance as inoculants in agriculture.

A Diagnosis of Camptodactyly With Benign Joint Hypermobility Syndrome in a Patient Presenting With Fixed Flexion Deformity of the Fingers and Striae.

Camptodactyly is a genetic disorder that causes fixed flexion deformity of one or more fingers of single or both hands. It is very rare and the occurrence is very low amongst the children. It is linked to a handful of congenital connective tissue syndromes. It is passed onto generations with reduced expressivity. However, its association with benign joint hypermobility syndrome is rarely known. Joint hypermobility syndrome is a condition where there is extreme joint flexibility and it is related to a set of articular and extra-articular sequelae. We herein report a case of camptodactyly with benign joint hypermobility syndrome in a patient presenting with fixed flexion deformity of the fingers, joint hyperextensibility, and striae.