Nor Azwady Abd Aziz

Evaluation on physical, chemical and biological properties of casts of geophagous earthworm, Metaphire tschiliensis tschiliensis

Earthworms are soil dwellers that have profound effects on soil ecosystem. Their feeding and burrowing activities help to incorporate soil particles with organic matter and redistribute them back into the soil via casts. The casts produced enhance microbial activities in soil that promote nutrient cycling. The present study was carried out to examine the physical, chemical and biological properties of casts produced by soil dwelling earthworm, Metaphire tschiliensis tschiliensis. Prior to inoculation of earthworms, the soil was incubated for two weeks at room temperature with moisture content of 20%. Worm worked soil and earthworm casts produced were collected for analysis after one month. Our results demonstrated that earthworm casts contained higher organic matter (9.84 ± 0.60%) and humic acid (1.33 ± 0.25%) compared to bulk soil. Total N, Ca, S, Al and Zn contents were also found to be higher in earthworm casts. Besides that, earthworm casts exhibited higher colony forming units (CFU), indicating the presence of higher microbial population. The study suggested that cast produced by M. tschiliensis tschiliensis could improve the physical and chemical properties of the soil. It also contained higher microbial population compared to soil without earthworm.

Rapid biodegradation of polycyclic aromatic hydrocarbons (PAHs) using effective Cronobacter sakazakii MM045 (KT933253)

Graphical abstract

Relationship between Pb and Cd accumulations in house crow, their habitat, and food content from Klang area, Peninsular Malaysia

Heavy metal pollution has become a global concern due to accumulation in tissue and transferable effects to humans via the food chain. This study focused on monitoring the accumulation of cadmium (Cd) and lead (Pb) in surface soil and body content: bone, heart, brain, liver, lung, muscle, kidney, feathers, feces, and gizzard contents of house crow Corvus splendens in the Klang region, Malaysia. The results revealed the occurrence of Pb and Cd in all biological samples from house crows, food contents, and surface soil samples. Heart and kidney accrued high amounts of Cd, while high amounts of Pb were found to accumulate in bones and feathers. Major discrepancies were also discovered in the concentrations of metals between juvenile and adults, as well as female and male bird samples. Concentrations of Pb and Cd in house crow internal tissues correlated significantly with that of bird feathers, but none could be established with that of surface soil. In addition, a significant correlation was observed between Pb concentration in the internal tissues to that of the feces, but the same was not the case when compared with the surface soil concentration. Metal accrual in the house crows feathers and feces may be through a long-term transmission via the food chain, which are eliminated from feathers via molting. This may suggest the utility of molted breast feathers of house crow in the bio-monitoring of Cd and Pb contamination, whereas feces of house crow appear only to be suitable for the bio-monitoring of Pb contamination.

Potential role of endogeic earthworm Pontoscolex corethrurus in remediating banana blood disease: a preliminary observation

Blood disease is a destructive bacterial infection that causes severe yield loss to the banana industry. Ideally, an environmental friendly yet practical approach is necessitated in the search for effective treatment against the disease. Endogeic earthworms are soil biota that help in improving soil physico-chemical and biological properties and thuspromote plant health. The present study assessed the effect of Pontoscolex corethrurus on banana infected by blood disease. The effect of earthworms was evaluated through observations on stem and root morphology, anatomy and total phenolic contents (TPC). P. corethrurus was inoculated into polybags planted with banana plantlets; inoculation of blood disease bacterium (BDB) into the roots of the plantlets was done using a drenching method. Stem and root sections of the plantlets were preserved in FAA for histological study upon harvest. The remaining sections were freeze-dried for TPC analysis. Root sections of plantlets infected with BDB showed lower root biomass compared to the control and earthworm-inoculated plantlets. Observations under microscope also showed that tissue necrosis at the vascular bundles of infected roots were more severe compared to the earthworm-inoculated and unaffected plantlets. Plantlets inoculated with earthworms had the highest root TPC, followed by the unaffected plantlets and plantlets infected with BDB. Although infected plantlets with earthworm inoculation showed disease symptoms, the disease severity was slightly less. The results suggested the potential role of P. corethrurus in improving plant health for disease management and sustainable agriculture.