Heavy metal contamination is a crucial problem to solve because it leads to poisoning, phytotoxicity and soil fertility reduction. Microbial assisted bioremediation is proposed to solve the problem due to their ability to adapt and mitigate heavy metal adverse effect. This study was aimed to determine the diversity of bacterial colonies, the level of tolerance of bacterial isolates, and the ability of bacterial isolates to produce plant growth hormone and secondary metabolites. Heavy metal tolerance tests were carried out on 6 bacterial isolates, namely S1aB1, S1aB2, S1bB4, S2aB5, S3aB7, and S4bB11. S4bB11 was found as the isolate with the highest growth pattern based on spectrophotometry optical density (OD) when the isolate grown in Pb and Hg supplemented environment. Further GC-MS analysis on S4bB11 detected several metabolites that play a role in heavy metal bioremediation namely α-Ketoglutaric acid, diaminopimelic acid and mannose. In addition, the presence of growth hormones (3indole acetic acid and kinetin) were also detected. Thus, the bacteria was predicted to have dual functions, both as industrial waste bioremediator and biofertilizer.

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Jatropha curcas Linn. is one of shrubs mainly exist in tropical area. The research team has succeeded to produce several excellent hybrid genotypes which then were planted to be tested its production capacity for 5 yr. Those genotyes were: genoptype 5 (HS49 × SP34), genotype 6 (HS49 × SM35), genotype 7 (HS49 × IP1A), and genotype 18 (SP16 × SM35). This research aims at finding out the production capacity of several hybrid genotypes of J. curcas Linn. which was conducted for 5 yr in Kedung Pengaron, Pasuruan. The research was arranged in Randomized Complete Block Design with four repetitions. Each block contained 20 plants, with plant treatment of hybrid result of genotype 5 (JC5), 6 (JC6), 7 (JC7), 18 (JC18) and two comparators of IP3A and IP3P. Observation was conducted on the number of fruit bunches and fruit on each plant, the number of fruit per plant, seed dry weight per plant. The study showed that J.curcas hybrids of genotypes JC5, JC7 and JC18 had higher production capacity (in term of number of fruit per plant, seed dry weight per plant and dry weight of 100 seeds) than other genotypes (JC6, IP3A, IP3P) in environment with drought stress.

Plant growth-promoting bacteria (PGPB) have become an important subject of research to increase maize production. The PGPB consortium should provide more benefits than single or dual inoculation. This study aimed to investigate the effect of a PGPB consortium on improving maize growth and yield. The field experiment used a split-plot design. The main plot consisted of three maize varieties (Talenta, Pertiwi-3, and Bisma), and the subplot consisted of three formulations of PGPB consortia [endophytic bacteria isolates, <em>Acetobacter</em> sp., cellulolytic, and ligninolytic (F1); endophytic bacteria isolates<em>, </em><em>Azospirillum </em>sp., cellulolytic, and ligninolytic (F2); and endophytic bacteria isolates, cellulolytic, ligninolytic, <em>Acetobacter </em>sp., and <em>Azospirillum </em>sp. (F3)] and one control. PGPB consortia formulation did not influence maize growth significantly, but maize varieties did. Pertiwi-3 showed the highest value in all growth variables, followed by Bisma and Talenta, respectively. The effect of PGPB consortia formulation upon ear fresh and dry weight depends upon the maize variety, and Pertiwi-3 showed the highest value in yield variables. PGPB consortia formulation 2 was the most effective to apply for Pertiwi-3 cultivation, while PGPB consortia formulation 3 produced higher yields for Talenta and Bisma. These findings indicated that specific PGPB formula could improve the yield for specific maize varieties.

Several bacteria have been observed as tolerant to the plastic waste according to previous studies. However, its ability as in biodegradation of plastic and biological fertilizers has not been previously tested. Therefore this research is intended to test the potential ability of these bacteria as in biodegradation of plastic waste and biological fertilizer by using Gas Chromatography-Mass Spectrophotometry (GC-MS) technique. According to GC-MS analysis results on SP6 isolates as plastic-tolerant bacterial models, have obtained 5 specific secondary metabolites which act as biodegradation of plastic with the composition as follows: Malic acid (𝐶4𝐻6𝑂5) 1.85%, Xanthine (𝐶5𝐻4𝑁4𝑂2) 1.08%, Myo inositol (6𝐻12𝑂6) 1.32%, γ Glutamyl alanine (𝐶8𝐻14𝑁2𝑂5) 0.85% and Ribitol 5 phosphate (𝐶5𝐻13𝑂8𝑃) 1.30%. In addition, the isolate was also able to synthesize several phytohormonesan indicator for potential use as biofertilizer-with the composition as follows: α Aminobutyric acid3 (C4H9NO2) 1.20%, Indoleacetic acid (C10H9NO2) 1.85%, Kinetin (C10H9N5O) 1.19%, Kinetin glucoside (C16H19N5O7) 1,19 % and Benzyladenine 9 glucoside N6 (C18H21N5O5) 1.31%. It is therefore, the bacterium has a double potentiality not only to degrade plastics, but also to be used as a bio-fertilizer.