Evaluating Nitrogen-Containing Biosynthetic Products Produced by Saltwater Culturing of Several California Littoral Zone Gram-Negative Bacteria

Abstract

The biosynthetic potential of marine-sediment-derived Gram-negative bacteria is poorly understood. Sampling of California near-shore marine environments afforded isolation of numerous Gram-negative bacteria in the Proteobacteria and Bacteriodetes phyla, which were grown in the laboratory to provide extracts whose metabolites were identified by comparative analyses of LC-mass spectrometry and MSn data. Overall, we developed an assemblage of seven bacterial strains grown in five different media types designed to coax out unique secondary metabolite production as a function of varying culture conditions. The changes in metabolite production patterns were tracked using the GNPS MS2 fragmentation pattern analysis tool. A variety of nitrogen-rich metabolites were visualized from the different strains grown in different media, and strikingly, all of the strains examined produced the same new, proton-atom-deficient compound, 1-methyl-4-methylthio-β-carboline (1), C13H12N2S. Scaleup liquid culture of Achromobacter spanius (order: Burkholderiales; class: Betaproteobacteria) provided material for the final structure elucidation. The methods successfully combined in this work should stimulate future studies of molecules from marine-derived Gram-negative bacteria.

Effects of Continuous Nitrogen Fertilizer Application on the Diversity and Composition of Rhizosphere Soil Bacteria

“…Rhizosphere soil bacteria have various mechanisms that are deployed in response to the presence of N and phosphate–potassium fertilizers, and the inputs of these fertilizers can have both favorable and unfavorable effects on different bacterial communities ( Rousk et al, 2010 ). In the present study, we found that the average relative richness of the dominant bacteria, along with that of Actinobacteria , in the rhizosphere soil of wheat decreased significantly under the long-term application of N. Previous research has shown that the richness of bacteria such as Patescibacteria and Bacteroidetes has a positive effect on N-containing biosynthetic products ( Lorig-Roach et al, 2017 ), and we found that the richness of bacteria in these two phyla showed a very significant correlation with wheat yield in the first 5 years of continuous N application, during which time the average relative richness of Patescibacteria and Bacteroidetes initially increased and then decreased with an increase in N application, reaching the highest value under N 180 . Thus, a decrease in the relative richness of the dominant species of rhizosphere soil bacteria is probably one of the factors leading to a decrease in wheat yield under long-term N fertilization.…”

The value of universally available raw NMR data for transparency, reproducibility, and integrity in natural product research

“…These data should be useful in the future as new MYC analogues are isolated or synthesized. The value of obtaining and using HMBC-derived 1 J CH data to make functional group assignments for compounds possessing ratios of H/(C + Z) < 0.5 was recently demonstrated 222. It appears that accessing such data has become a “forgotten art”, yet the measurement shown in Fig.…”

Marine natural products

“…New compounds from the Firmicutes genera Bacillus, Geobacillus and Thermoactinomyces include 201-216, [98][99][100][101][102][103][104][105][106] while new NPs from the Proteobacteria genera Pseudoalteromonas, Pseudomonas, Pseudovibrio, Vibrio, Thalassiosira, Enhygromyxa and Labrenzia include 217-241. [107][108][109][110][111][112][113][114][115][116] Closer inspection of the spectroscopic and spectrometric data (or lack thereof) presented in several articles reporting new marine bacteria NPs, suggest that the structure assignment of several compounds (202-205, 99 The rst total syntheses of the marine-derived bacteria compounds neomaclafungin A 242, 117 usabamycins A and C, 118 (À)-marinisporolide C, 119 seoaracenes A and B, 120 actinoranone 243, 121 enhygrolide A, 122 discoipyrroles C and D, 123,124 and metagenetriindole A 125 has been achieved.…”