Thermal Hydrolysis Pretreatment-Anaerobic Digestion Promotes Plant-Growth Biostimulants Production from Sewage Sludge by Upregulating Aromatic Amino Acids Transformation and Quinones Supply

In 110~190°C for 15~75min excess sludge thermal hydrolysis test, investigated the dissolution rate of the volatile suspended solids, Sludge SCOD, TCOD concentration change in composition of organic acids in the supernatant, and analysis the improvement of the anaerobic digestion performance. The results show that, with the increase of thermal hydrolysis temperature and extension of time, sludge supernatant on SCOD, VFA rising. At 190 °C, 75min conditions, SCOD, VFA reached the maximum 6674mg / L2630mg/ L; Sludge organic solids dissolved and the release of COD, etc. mainly in the first 45 min to complete, little change after 45min. When thermal hydrolysis temperature between 90~170°C, anaerobic digestion performance increase with temperature rise, When the temperature is higher than 170 °C, the sludge anaerobic digestion performance begins to decline.

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Metabolic Profiling of PGPR-Treated Tomato Plants Reveal Priming-Related Adaptations of Secondary Metabolites and Aromatic Amino Acids

Metabolites ◽

10.3390/metabo10050210 ◽

2020 ◽

Vol 10 (5) ◽

pp. 210 ◽

Cited By ~ 3

Author(s):

Msizi I. Mhlongo ◽

Lizelle A. Piater ◽

Paul A. Steenkamp ◽

Nico Labuschagne ◽

Ian A. Dubery

Keyword(s):

Amino Acids ◽

Plant Growth ◽

High Performance ◽

Induced Defense ◽

Aromatic Amino Acids ◽

Plant Growth Promoting Rhizobacteria ◽

Defense Responses ◽

Metabolic Reprogramming ◽

Post Inoculation ◽

Targeted Analysis

Plant growth–promoting rhizobacteria (PGPR) are beneficial microbes in the rhizosphere that can directly or indirectly stimulate plant growth. In addition, some can prime plants for enhanced defense against a broad range of pathogens and insect herbivores. In this study, four PGPR strains (Pseudomonas fluorescens N04, P. koreensis N19, Paenibacillus alvei T19, and Lysinibacillus sphaericus T22) were used to induce priming in Solanum lycopersicum (cv. Moneymaker) plants. Plants were inoculated with each of the four PGPRs, and plant tissues (roots, stems, and leaves) were harvested at 24 h and 48 h post-inoculation. Methanol-extracted metabolites were analyzed by ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). Chemometric methods were applied to mine the data and characterize the differential metabolic profiles induced by the PGPR. The results revealed that all four strains induced defense-related metabolic reprogramming in the plants, characterized by dynamic changes to the metabolomes involving hydroxycinnamates, benzoates, flavonoids, and glycoalkaloids. In addition, targeted analysis of aromatic amino acids indicated differential quantitative increases or decreases over a two-day period in response to the four PGPR strains. The metabolic alterations point to an altered or preconditioned state that renders the plants primed for enhanced defense responses. The results contribute to ongoing efforts in investigating and unraveling the biochemical processes that define the PGPR priming phenomenon.

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