RESUMEN
This paper provides a mini review of liquid biofertilizers, which have been proven to perform better than the other forms in lasting for longer periods of time, improving crop quality, and requiring less amounts for application. The production of liquid biofertilizers, types of liquid inoculants, and their effect on plant growth are covered in this review. Liquid biofertilizers can be made from wastes and by-products of several industries, making zero or near-zero discharge possible and thus gearing towards circular economy. Despite their usefulness in enhancing crop quality and eco-friendliness, in order to compete with chemical fertilizers, there are a number of challenges to overcome, such as extending the shelf life, making them more susceptible to seasonal climate conditions and soil types, and development of suitable machineries for production and application. More field trials, cost-benefit analysis and long-term studies should also be evaluated for commercialization purposes.
RESUMEN
BACKGROUND: Isoprene is the most abundantly produced biogenic volatile organic compound (BVOC) on Earth, with annual global emissions almost equal to those of methane. Despite its importance in atmospheric chemistry and climate, little is known about the biological degradation of isoprene in the environment. The largest source of isoprene is terrestrial plants, and oil palms, the cultivation of which is expanding rapidly, are among the highest isoprene-producing trees. RESULTS: DNA stable isotope probing (DNA-SIP) to study the microbial isoprene-degrading community associated with oil palm trees revealed novel genera of isoprene-utilising bacteria including Novosphingobium, Pelomonas, Rhodoblastus, Sphingomonas and Zoogloea in both oil palm soils and on leaves. Amplicon sequencing of isoA genes, which encode the α-subunit of the isoprene monooxygenase (IsoMO), a key enzyme in isoprene metabolism, confirmed that oil palm trees harbour a novel diversity of isoA sequences. In addition, metagenome-assembled genomes (MAGs) were reconstructed from oil palm soil and leaf metagenomes and putative isoprene degradation genes were identified. Analysis of unenriched metagenomes showed that isoA-containing bacteria are more abundant in soils than in the oil palm phyllosphere. CONCLUSION: This study greatly expands the known diversity of bacteria that can metabolise isoprene and contributes to a better understanding of the biological degradation of this important but neglected climate-active gas. Video abstract.