A novel micro‐organism for removing excess ammonia‐N in seawater ponds and the effect of Cobetia amphilecti on the growth and immune parameters of Litopenaeus vannamei

Abstract

To investigate the feasibility of using micro‐organisms for ammonia‐N removal, six strains were isolated from Chinese white shrimp, Fenneropenaeus chinensis, seawater culture ponds in Dongying (Shandong, China). Of these, strain DY‐01, which exhibited the highest capacity to degrade ammonia‐N, removed 61.7% of the total ammonia‐N (50 mg/L) in 8 hr. An investigation of the factors affecting the removal efficiency indicated the optimum conditions to be 30°C, pH 8.0, and a salinity level of 30 g/L; 16S rDNA gene sequencing and biochemical analysis identified strain DY‐01 as Cobetia amphilecti, which has not previously been reported to degrade ammonia‐N. This strain also boosted the growth of Pacific white shrimp, Litopenaeus vannamei (p < .05), at a concentration of 107 CFU/mL, with no harmful effects on the shrimp's immune system. This study has thus identified a novel aerobic nitrifying bacterium that is potentially an excellent candidate for improving the water quality in mariculture ponds.

Characterization of Vibrio sp. strain AB15 and Pseudomonas fluorescens strain NB14 from the biofloc of shrimp culture ponds capable of high ammonia and nitrite removal efficiency

“…As for immune parameters, the total hemocyte count, phagocytic percent, and antibacterial activity were all enhanced, with no significant difference between the treatments and control group, according to Huang et al (2017) and Lv et al (2019). In this study, all immune parameters of L. vannamei showed significant differences in comparison with the control, which confirmed that AB15 and NB14 owned high ability to enhance immunity of L. vannamei .…”

“…Temperature and the initial pH usually make effects on the growth of microorganism and their absorption and utilization of substances via changing enzyme activity (Dong & Cai, 2001; Verstraete & Focht, 1977; Wang, Chang, Yu, Li, & Xu, 2007). Most of the reported NH 4 + ‐N and NO 2 − ‐N removal bacteria have optimum temperatures ranging from 25 to 40°C (Huang et al, 2017; Saleh‐Lakha et al, 2009; Qing et al, 2018) and the optimal pH is often at the scope of pH 7.0–9.0 (Huang et al, 2017; Lei, Jia, Chen, & Hu, 2019; Lv, Pan, Zhang, Li, & Zhang, 2019), which were paralleled with the results of strain AB15 at 25°C, pH 7.5, and strain NB14 at 30°C and pH 8.0 in this study. Beyond that, NaCl is essential to enzyme activities of the strain originated from the marine ecosystem (Duan, Fang, Su, Chen, & Lin, 2015), while cell plasmolysis and activity loss of microorganism caused by too high salinity may lead to the deteriorated ammonia removal efficiency (Uygur & Kargi, 2004).…”

Complete genome sequencing and comparison of two nitrogen-metabolizing bacteria isolated from Antarctic deep-sea sediment

“…However, the genome assembly lengths of Cobetia amphilecti N-80, Cobetia amphilecti B2M13 and Cobetia amphilecti KMM296 are 4.16 Mb, 4.29 Mb, and 3.97 Mb, with 1, 27, and 97 scaffolds, respectively. Cobetia amphilecti N-80 is more studied than Halomonas profundus 13 and has been shown to possess ammonia-N degrading [59], a novel glutaminase-free L-asparaginase [60], antibiofilm activity and biopreservative effects on meat products [61], bacteriocinogenic potential [62] and so on. This may be due to the wider distribution of Cobetia amphilecti N-80, which is found in seawater culture ponds [59], mangrove sediments [60], ready-to-cook meats [61], ecosystems within the Sea of Japan [62] and elsewhere.…”

“…Cobetia amphilecti N-80 is more studied than Halomonas profundus 13 and has been shown to possess ammonia-N degrading [59], a novel glutaminase-free L-asparaginase [60], antibiofilm activity and biopreservative effects on meat products [61], bacteriocinogenic potential [62] and so on. This may be due to the wider distribution of Cobetia amphilecti N-80, which is found in seawater culture ponds [59], mangrove sediments [60], ready-to-cook meats [61], ecosystems within the Sea of Japan [62] and elsewhere. However, there are no detailed reports on its nitrification and denitrification abilities.…”

“…In addition, cloning and expression have been performed for several of its functional genes, such as ectABC and its promotor sequence in Cobetia marina CICC10367 [7], the L-asparaginase gene (CobAsnase) in Cobetia amphilecti AMI6 [8], and alkaline phosphatase in Cobetia marina [9]. Cobetia amphilecti has the ability to remove excess ammonia-N in seawater ponds, removing 61.7% of the total ammonia-N (50 mg/L) in 8 h [10]. However, no analysis was conducted at the genetic level.…”