Suitability of inorganic coagulants for algae-laden water treatment: Trade-off between algae removal and cell viability, aggregate properties and coagulant residue.

Inorganic coagulants could effectively precipitate algae cells but might increase the potential risks of cell damage and coagulant residue. This study was conducted to critically investigate the suitability of polyaluminum (PAC), FeCl3 and TiCl4 for algae-laden water treatment in terms of the trade-off between algal substance removal, cell viability, and coagulant residue. The results showed that an appropriate increase in coagulant dosage contributed to better coagulation performance but severe cell damage and a higher risk of intracellular organic matter (IOM) release. TiCl4 was the most destructive, resulting in 60.85% of the algal cells presenting membrane damage after coagulation. Intense hydrolysis reaction of Ti salts was favorable for the formation of larger and more elongated, dendritic structured flocs than Al and Fe coagulants. TiCl4 exhibited the lowest residue level and remained in the effluents mainly in colloidal form. The study also identified charge neutralization, chemisorption, enmeshment, and complexation as the dominant mechanisms for algae water coagulation by metal coagulants. Overall, this study provides the trade-off analyses between maximizing algae substance removal and minimizing potential damage to cell integrity and is practically valuable to develop the most suitable and feasible technique for algae-laden water treatment.

Genomic Insights into Combating Anthracnose with an Endophytic Bacillus amyloliquefaciens Strain.

Anthracnose, caused by Colletotrichum spp., is a common disease of Camellia oleifera. In this study, a Bacillus amyloliquefaciens strain, GZY63, was isolated from fruit of the anthracnose-resistant cultivar of Ca. oleifera "Ganzhouyou7." Plate confrontation assays and field experiments demonstrated the strong inhibitory effect of GZY63 on anthracnose, and this strain exhibited broad-spectrum resistance to nine pathogenic Colletotrichum spp. This strain shows potential as a fungicide alternative, but genetic information on this strain is critical for its optimal use. Combining Illumina and Nanopore sequencing, we assembled a high-quality circular genome of GZY63 that contained no plasmids. The GZY63 complete genome was approximately 3.93 Mb and had an average guanine-cytosine content of 46.5%. The genome comprised 4,024 predicted coding sequences and 12 types of gene clusters involved in secondary metabolite production. This genome information provides insights into the mechanism underlying the antagonistic impact of the GZY63 strain on anthracnose and its symbiotic relationship with Ca. oleifera.