No abstract

Plant Growth Promoting (PGP) Endophytic bacteria are used as an alternative biofertilizer to support soil health and plant productivity. This research aimed to isolate, analyze the potential, and identify the endophytic bacteria of Robusta and Arabica coffee plants as biofertilizer agents. Endophytic bacteria were isolated from the roots of coffee plants and tested for their potential to produce IAA, phosphate-solubilizing, and nitrogen fixation. Potential endophytic bacterial isolates were identified based on 16S rDNA sequence similarity. Total isolates from Robusta coffee consisting of ten IAAproducing bacteria, eight phosphate-solubilizing, and seven nitrogen fixation bacteria isolates. Total isolates from Arabica coffee roots were 12 isolates of IAA-producing bacteria, seven isolates of phosphate-solubilizing bacteria, and six isolates of nitrogen fixation bacteria. The highest potential of the isolate from Robusta roots was SS.E2 isolate to produce IAA 110.73 μg.mL -1 ; SS.P3 isolate to dissolve phosphate 4.42 μg.mL -1 , and SS.N2 isolate to produce ammonium 3.15 μg.mL -1 . The highest potential of the isolate from Arabica roots was SW.E9 isolate to produce IAA up to 257.16 μg.mL -1 ; SW.P5 isolate to dissolve phosphate up to 4,55 μg.mL -1 ; and SW.N6 isolate to produce ammonium up to 1.16 μg.mL -1 . Isolates SS.E2, SW.E9, SS.P3, SW.P5, SS.N2, and SW.N6 were respectively identified as Bacillus cereus ATCC 14579, Bacillus cereus ATCC 14579, Rahnella aquatilis B35, Kluyvera intermedia TPY16, Rahnella aquatilis B35, and Pseudomonas tolaasii NCPPB 2192. Potential PGP isolates can be developed as biofertilizer agents for the coffee plant.

Aims:The objective of this research was to isolate caffeine-degrading bacteria from coffee pulp waste in Indonesia and characterize their caffeine degradation activity. Methodology and results: The caffeine-degrading bacteria were isolated from coffee pulp wastes of Coffea arabica and C. canephora. These isolates were selected based on their caffeine degradation activity. The identification and biochemical properties of the best isolate were conducted via 16S rDNA sequence analyses and by using the Microbact kit. Meanwhile, caffeine degradation activity of this bacteria was analyzed by using LC-MS/MS. The results indicated that fourteen bacterial isolates were able to degrade caffeine. The highest caffeine degradation activity was performe d by isolate KRM9 at the rate of 99.26 ± 0.01%, on a caffeine medium after 24 h of incubation. Based on the 16S rDNA analyses, the KRM9 isolate was identified as Pseudomonas monteilii. Till present, this species has not been reported as a caffeine-degrading bacterium. However, LC-MS/MS analysis indicated that caffeine was degraded by P. monteilii KRM9 and theobromine was not the secondary metabolite of caffeine degradation. Conclusion, significance and impact of study: Pseudomonas monteilii KRM9 was detected as a new isolate of caffeine-degrading bacteria. This bacterium can be introduced as an agent to degrade caffeine from coffee pulp waste. It is expected that further research can be conducted on the overall mechanism of caffeine degradation by P. monteilii KRM9.

The radical scavenging capacities and DNA damage protection of fermented melinjo (Gnetum gnemon) flour were investigated to determine its potential use as a nutraceutical ingredient. Fermented melinjo flour was prepared using a Lactobacillus fermentum starter culture. The fermented and unfermented melinjo flours were examined for antioxidant activities using different standard methods. The results indicated that fermented flour had significantly (p < .05) higher phenolic content (10.61 mg Galic acid equivalent (GAE)/g) than the unfermented flour (8.61 mg GAE/g). High‐performance liquid chromatography‐Diode Array Detector detection demonstrated that fermentation resulted in a loss of phenolic compounds, such as gnetifolin E, gnemonoside E, and resveratrol but not gnetin C. Subsequently, fermentation led to marked increases (significant, p < .05) in the radical scavenging abilities of DPPH, ABTS, hydroxyl, and hydrogen peroxide. In addition, fermented flour extract possessed superior resistance to oxidative damage of DNA by Fenton's reagent. Overall, the antioxidant enhanced melinjo flour was successfully produced and could be used as a functional food to promote the health and nutrition of consumer. Practical applications The Gnetum gnemon tree is popularly known in Indonesia as melinjo. Melinjo seeds are regularly consumed as crackers or cookies made from ground flour. These seeds are a suitable nutritional supplement with high bioavailability. In this study, the antioxidant activity of fermented melinjo flour was increased after Lactobacillus fermentum fermentation. In addition, some bioactive compounds were produced during fermentation. The fermented products can be used as nutritional supplements for the prevention and control of degenerative diseases. Therefore, this study provides a simple and effective strategy to improve the nutritional value of melinjo flour.

Aims:The objective of the research was to get the potential cellulolytic bacteria which was caffeine tolerance from Indonesian coffee pulp waste. Methodology and results: The cellulolytic bacteria were isolated from coffee pulp wastes of Coffea arabica and C. canephora. These isolates were selected based on their cellulose hydrolysis, CMCase activity, and caffeine tolerance. The density of cellulolytic bacteria of C. arabica pulp waste was 4.7 ± 3.5 × 10 6 CFU/g, and that of C. canephora pulp waste was 1.5 ± 1.5 × 10 6 CFU/g. Among 61 cellulolytic bacterial isolates, 24 isolates formed clear zones on CMC medium with Gram iodine flooding. Three isolates (CRM10, CRM1, and CRM12) from C. canephora pulp waste had the highest cellulolytic activity. Based on the CMCase activity, it was indicated that an isolate of CRM10 showed the highest CMCase activity with 3.38 ± 0.65 U/mL. This bacteria had tolerance ability to caffeine until 0.4% on nutrient agar medium. Isolates of CRM10 had similarity to Bacillus subtilis based on 16S rDNA sequence. Conclusion, significance, and impact of study: CRM10 was identified as Bacillus subtilis and considered as a potential isolate to degrade cellulose of coffee pulp waste that contained caffeine. .