Stronger effect of maize rhizosphere than phosphorus fertilization on soil phosphatase activity and associated bacterial communities in acidic soil: distinct influences on phoC- and phoD-harboring bacteria

Aims The bacteria phoC and phoD genes encode acid and alkaline phosphatase (ACP and ALP), respectively, which mineralize organic phosphorus (P) to inorganic P. The relative importance of P fertilization and the plant rhizosphere on soil phosphatase activities and associated bacterial communities in acidic soils are poorly understood; whether phoC- and phoD-harboring bacterial communities display different responses remains undetermined. Methods Maize was grown in acidic soil supplemented with 0 (P0), 20 (P20), and 200 (P200) mg P2O5 kg− 1 for 42 days. Maize biomasses, plant nutrients, soil properties, phosphatase activities, and associated bacterial abundance and community composition were determined. Results Relative to bulk soils, rhizosphere showed increased ACP and ALP activities, phoC and phoD gene abundance, but these effects were reduced in strength with P200 treatment, except for phoC gene abundance. The rhizosphere effect increased α-diversity of phoC-harboring bacteria under P fertilization but reduced α-diversity of phoD-harboring bacteria under P0 and P20 treatments. The rhizosphere significantly influenced both phoC- and phoD-harboring bacterial community compositions, with stronger effect on phoD-harboring bacteria; while P fertilization affected phoD-harboring bacteria but not phoC-harboring bacteria. Immigrated and extinct species play important roles in reshaping phoC- and phoD-harboring bacterial communities, respectively, in response to the rhizosphere effect. Conclusions Compared with P fertilization, the maize rhizosphere more strongly influenced soil phosphatase activities and phoC- and phoD-harboring bacterial communities in acidic soils, with phoD-harboring bacteria responding more strongly to the rhizosphere effect and P fertilization. Notably, the strength of the rhizosphere effect heavily relied on P fertilization level.

Pathological and biochemical index changes in different tissues of Cyprinus carpio exposed to cadmium

Background: Cadmium (Cd) is among the most toxic metals and is widely distributed in aquatic environments. Objective: Histopathological lesions and biochemical indices can be used to reflect the toxic effects of cadmium in fish target organs. Methods: In the present study, the common carp Cyprinus carpio was exposed to 0.5 mg/L of CdCl2 for 21 days. Histopathological analyses were performed in the spleen, liver, kidney, gills and head kidney tissues of C. carpio, and tissue sections were stained with hematoxylin-eosin (HE) and observed under an optical microscope. The acid phosphatase, alkaline phosphatase, and lysozyme activities were determined. Results: The results showed that there were various pathological changes in five major tissues of C. carpio. The kidney, gills, and liver were the most affected organs during cadmium exposure, and deformation and disorganization of epithelial cells, vacuolization formation, serious hemorrhages and necrosis were also observed. In addition, 0.5 mg/L cadmium exposure significantly increased serum lysozyme and acid phosphatase activities and inhibited alkaline phosphatase activity. The present study showed that cadmium stress causes significant pathological tissue changes and influences lysozyme, acid phosphatase and alkaline phosphatase activities in C. carpio. Acid phosphatase and lysozyme activities are sensitive to cadmium. Conclusion: In conclusion, the toxicity of cadmium caused varying degrees of pathological and biochemical changes in fish tissues in C. carpio.

HETEROSIDASE ACTIVITIES EXTRACTED FROM THE SEEDS OF THE PITS OF SIX MANGO (MANGIFERA INDICA L) CULTIVARS

Heterosidases are enzymes capable of releasing bioactive moleculesused in cosmetics,nutrition, medicine and in manyotherfields.For thiswork, the presence of glycosidases withheterosidaseactivitiesweredetectedin the seed of the kernels of six cultivars of mangoes (Mangiferaindica L) cultivatedin the region of DALOA (Cote dIvoire) in orderto select new enzymatic sources to original activities. To do this, the crudeenzymaticextractsweretakenfrom the almonds of kernels of the LOCAL, KENT, CAMEROUN, TARDIVE, GREFFE and SUCETTE cultivars of mangoes. Specificactivitiesweredeterminedfromtheseextractsand thencompared. The heterosidaseactivitiestestedwerethose of the β-glucosidase, β-galactosidase, β-fucosidaseand phosphatase activities. All theseactivitieshave been present in thesecultivars.However, thehighestspecificactivitieswerethose of the LOCAL cultivarfollowed in general by those of the GREFFE cultivar. It thereforeemergedfromthisstudythattheseseeds have enzymaticequipment capable of degradingheterosides. Thesedifferent glycosidases couldconstitute important enzymatictools for the valorization of food and non-foodbiomolecules of agricultural rawmaterials and for the development of industry.

Use of Slaughterhouse Sludge in the Bioremediation of an Oxyfluorfen-Polluted Soil

The use of organic matter is a highly accepted environmental practice among scientists for the bioremediation of polluted soils. In this manuscript we study under laboratory conditions the bioremediation capacity of a new biostimulant obtained from slaughterhouse sludge in a soil polluted by the oxyfluorfen at a rate of 4 l ha−1 (manufacturer’s rate recommended) over a 90-day period. We determined its effects on dehydrogenase, urease, β-glucosidase and phosphatase activities, the soil microbial community structure and the evolution of the herbicide in soil. Possibly due to the high content of low molecular weight proteins in the biostimulant, the enzymatic activities were stimulated mainly at the beginning of the experiment. Soil biological parameters were inhibited in oxyfluorfen-polluted soil. At the end of the experiment and compared with the control soil, dehydrogenase, urease, β-glucosidase, and phosphatase activities significantly decreased by 47.8%, 50.5%, 36.4%, and 45.5% in the oxyfluorfen-polluted soil. At 5 days into the experiment, the use of the biostimulant in oxyfluorfen-polluted soils decreased soil enzymatic activities and microbial community inhibition. At the end of the incubation period the oxyfluorfen concentration had decreased by 60% in the polluted soil and amended with biostimulants. These results suggested that the use of this biostimulant with higher amounts of low molecular weight proteins and peptides had a positive effect on the remediating oxyfluorfen-polluted soils. Therefore, this study provides the use of a new biostimulant obtained from slaughterhouse sludge by enzymatic hydrolysis processes used in the bioremediation of a soil polluted by the oxyfluorfen herbicide.

Effect of BMP- 2, -4, and -7 on Proliferation and Osteogenic Differentiation in Cultured Human PDLSCs

Aim To investigate the effects of bone morphogenetic proteins (BMPs) 2, 4, and 7 on proliferation and osteogenic differentiation in human periodontal ligament stem cells (PDLSCs). Methods PDLSCs were isolated by an immunomagnetic method. Expression of cell surface antigens CD146, CD44, and CD34, and pluripotency (osteogenic and adipogenic) were measured. Cultured PDLSCs were treated, in dose- and time-dependent experiments, with single BMPs, with 1:1 combinations, and with a mix of all three BMPs (1:3 each). For dose-dependent experiments, PDLSCs were incubated for 12 d with media containing BMPs at 0, 10, 25, 50, and 100 ng/ml. For time-dependent experiments, PDLSCs were treated with media containing 50 ng/ml BMPs for 0, 3, 6, 12, and 24 d. Cell growth and alkaline phosphatase activities were measured by MTT and an enzyme kit. Immunohistochemistry and western blotting were used to detect osteogenic differentiation-related proteins, i.e., osteocalcin, bone sialoprotein, collagen type I, and collagen type III. Results PDLSCs displayed CD146 (93%) and CD44 (91.2%) positive expression; CD34 (1.8%) showed negative expression. All cells exhibited osteogenic and adipogenic potential. The proliferation and alkaline phosphatase activities of PDLSCs treated with the aforesaid single and combined BMPs increased in a dose- and time-dependent manner; proliferation and alkaline phosphatase activity were greater with the BMP combinations. Compared with the control group, the levels of osteogenic differentiation-related proteins increased markedly in PDLSCs treated with 50 ng/ml BMPs for 12 d, whereas no significant differences were observed between the different BMP treatments. Conclusion BMP-2, -4, and -7, singly and in combination, promoted development and osteogenic differentiation of PDLSCs, and both cellular outcomes were more pronounced with BMP combinations.

Regulation of TDP-43 phosphorylation in aging and disease

Insoluble inclusions of phosphorylated TDP-43 occur in disease-affected neurons of most patients with amyotrophic lateral sclerosis (ALS) and about half of patients with frontotemporal lobar degeneration (FTLD-TDP). Phosphorylated TDP-43 potentiates a number of neurotoxic effects including reduced liquid–liquid phase separation dynamicity, changes in splicing, cytoplasmic mislocalization, and aggregation. Accumulating evidence suggests a balance of kinase and phosphatase activities control TDP-43 phosphorylation. Dysregulation of these processes may lead to an increase in phosphorylated TDP-43, ultimately contributing to neurotoxicity and neurodegeneration in disease. Here we summarize the evolving understanding of major regulators of TDP-43 phosphorylation as well as downstream consequences of their activities. Interventions restoring kinase and phosphatase balance may be a generalizable therapeutic strategy for all TDP-43 proteinopathies including ALS and FTLD-TDP.