Vermistabilization of mango tree pruning waste with five earthworm species: A biochemical and heavy metal assessment.

Mango tree pruning results in high biomass output, which is a serious agricultural and environmental problem. Vermicomposting is a potential, fast and sustainable tool to address these challenges. For sixty days, the experiment was carried out in six vermireactors containing five earthworm species by Eudrilus eugeniae, Eisenia fetida, Aporrectodea rosea, Lumbricus rubellus, and Lampito mauritii, as well as composting (without earthworm) using mango tree pruning waste biomass along with cattle dung as an instant preferred feeding material for earthworms. The pH, TOC, C/N and C/P ratios of the waste were substantially reduced by the earthworm activity. However, after vermicomposting, the levels of macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, and Cu) and microbial count substantially increased. The TOC content of waste was reduced by 42-55%, and the C/N of vermicompost ranged from 5.58 to 11.38. The results showed that earthworm fecundity was highest in vermireactors containing Eudrilus eugeniae and Eisenia fetida. The current study was ultimately determine that vermicomposting using Eudrilus eugeniae or Eisenia fetida is an effective strategy for utilising mango tree pruning waste, ensuring environmental sustainability and improving farmer revenue.

Targeted DNA transposition in vitro using a dCas9-transposase fusion protein.

Homology-directed genome engineering is limited by transgene size. Although DNA transposons are more efficient with large transgenes, random integrations are potentially mutagenic. Here we present an in vitro mechanistic study that demonstrates efficient Cas9 targeting of the mariner transposon Hsmar1. Integrations were unidirectional and tightly constrained to one side of the sgRNA binding site. Further analysis of the nucleoprotein intermediates demonstrated that the transposase and Cas9 moieties can bind their respective substrates independently or in concert. Kinetic analysis of the reaction in the presence of the Cas9 target-DNA revealed a delay between first and second strand cleavage at the transposon end. This step involves a significant conformational change that may be hindered by the properties of the interdomainal linker. Otherwise, the transposase moiety behaved normally and was proficient for integration in vitro and in Escherichia coli. Specific integration into the lacZ gene in E. coli was obscured by a high background of random integrations. Nevertheless, Cas9 is an attractive candidate for transposon-targeting because it has a high affinity and long dwell-time at its target site. This will facilitate a future optogenetic strategy for the temporal control of integration, which will increase the ratio of targeted to untargeted events.