PMC

A) BMMC were pre-treated ± 12.5 mM lactic acid for the indicated time points and activated ± LPS (1 μg/mL) for 16 hours. B) BMMC were treated ± 12.5 mM lactic acid prior to, during, or following activation ± LPS (1 μg/mL) for 16 hours. C) BMMC were treated for 24 hours ± the indicated doses of lactic acid and activated ± LPS (1 μg/mL) for 16 hours. D) BMMC were treated for 24 hours ± 12.5 mM lactic acid and activated ± LPS (1 μg/mL) for 16 hours. ELISA analysis was used to determine supernatant cytokines. E) BMMC were treated for 24 hours ± 12.5 mM lactic acid and activated ± LPS (μg/mL) for 2 hours. RT-qPCR was used to determine IL-6 and actin mRNA expression. F) PMC were treated for 24 hours ± 12.5 mM lactic acid and activated ± LPS (1 μg/mL) for 16 hours. ELISA analysis was used to determine supernatant cytokine concentrations. Data are means ± SEM of 3 populations, representative of 3 independent experiments. **p < .01, *** p <0.001, ****p < .0001

Changes in the content of lactic acid in the system under different conditions. ADH: Alcohol dehydrogenase; LDH: Lactate dehydrogenase; NAD⁺: Nicotinamide adenine dinucleotide; ZIF@ADH/NAD-MSN/LDH: Core–shell nanocomposites prepared by ZIF-8 immobilized ADH, LDH, and MSN-NAD; MSN-NAD: Mesoporous silica nanoparticles immobilized nicotinamide adenine dinucleotide. (A) Lactic acid synthesis concentration of three experimental groups within 3 h at different temperatures. The same lowercase letters indicated that there was no significant difference in the concentration of lactic acid synthesis in the three experimental groups at the same temperature. Different lowercase letters indicated that there was significant difference in the lactic acid synthesis concentration of the three experimental groups at the same temperature. The same capital letters represent that there was no significant difference in the concentration of lactic acid synthesis in the same experimental group at different temperatures. Different capital letters indicated that the lactic acid synthesis concentration of the same experimental group at different temperatures was significantly different. (B) Lactic acid synthesis concentration of three experimental groups in 3 h at different pH. The same lowercase letters indicated that there was no significant difference in the concentration of lactic acid synthesis in the three experimental groups at the same pH. Different lowercase letters indicated that there was significant difference in the lactic acid synthesis concentration of the three experimental groups at the same pH. The same capital letters represented that there was no significant difference in the concentration of lactic acid synthesis in the same experimental group at different pH. Different capital letters indicated that there was significant difference in lactic acid synthesis concentration in the same experimental group under different pH conditions.

Enzymatic testing for lactic acid using Accuvin test strips.
Notes: Accuvin test strips from Accuvin LLC, St Napa, CA, USA. 180 mg/L lactic acid tested positive for lactic acid. 180mg/L lactic acid and PDLA dimer (N=2) tested negative for lactic acid. 180mg/L lactic acid and PDLA tetramer (N=4) tested positive for lactic acid. 180mg/L lactic acid and PDLA oligomer mixture tested negative for lactic acid.
Abbreviation: PDLA, polymer D-lactic acid.

(A–C). Values are presented as the mean±SD of three independent experiments. (D–F) HPLC analysis of lactic acid content in MG(Vector) cultures at 0%, 3%, and 5% NaCl, respectively, after 18 h. (G–I) HPLC analysis of lactic acid content in MG(PprI⁺) cultures at 0%, 3%, and 5% NaCl, respectively, after 18 h. Representative HPLC results from three independent analyses are shown. Lactic acid was identified by retention time compared with standard compound (lab stock). The amount of lactic acid was determined from the area under the peak detected at 240 nm using a calibration curve of lactic acid.