An Exploration of Seaweed Polysaccharides Stimulating Denitrifying Bacteria for Safer Nitrate Removal

Abstract

Excessive use of nitrogen fertilizer in intensively managed agriculture has resulted in abundant accumulation of nitrate in soil, which limits agriculture sustainability. How to reduce nitrate content is the key to alleviate secondary soil salinization. However, the microorganisms used in soil remediation cause some problems such as weak efficiency and short survival time. In this study, seaweed polysaccharides were used as stimulant to promote the rapid growth and safer nitrate removal of denitrifying bacteria. Firstly, the growth rate and NO3−-N removal capacity of three kinds of denitrifying bacteria, Bacillus subtilis (BS), Pseudomonas stutzeri (PS) and Pseudomonas putida (PP), were compared. The results showed that Bacillus subtilis (BS) had a faster growth rate and stronger nitrate removal ability. We then studied the effects of Enteromorpha linza polysaccharides (EP), carrageenan (CA), and sodium alginate (AL) on growth and denitrification performance of Bacillus subtilis (BS). The results showed that seaweed polysaccharides obviously promoted the growth of Bacillus subtilis (BS), and accelerated the reduction of NO3−-N. More importantly, the increased NH4+-N content could avoid excessive loss of nitrogen, and less NO2−-N accumulation could avoid toxic effects on plants. This new strategy of using denitrifying bacteria for safely remediating secondary soil salinization has a great significance.

Effects of Dietary Supplementation of Algae-Derived Polysaccharides on Morphology, Tight Junctions, Antioxidant Capacity and Immune Response of Duodenum in Broilers under Heat Stress

“…E. prolifera has good edible and medicinal values, showing anti-inflammatory and detoxifying effects [27]. E. prolifera contains abundant polysaccharides that exhibit many biological properties, including antioxidant, antiviral, antitumor, anti-inflammatory, immunomodulatory and antibacterial properties [28,29]. In our previous studies, the dietary inclusion of algae (E. prolifera)-derived polysaccharides (ADP) improved the intestinal barrier function of laying hens [30] and broilers [31].…”

Shelf-Life Extension of Large Yellow Croaker (Larimichthys crocea) Using Active Coatings Containing Lemon Verbena (Lippa citriodora Kunth.) Essential Oil

“…Previous research has shown that high percentage of neral in LVEO exhibits antimicrobial and antioxidant activities ( 19 ). Nevertheless, the antimicrobial activity of neral against several spoilage organisms has been well-documented in in-vitro trials and applied in food storage ( 20 , 21 ). However, some chemically active compounds of EOs are rarely present in food matrices, which have negative impact on the chemical food integrity, physical stableness, and the loss of bioactive activity of bioactive compounds ( 22 ).…”

Effects of Bacillus subtilis on Rose Growth Promotion and Rhizosphere Microbial Community Changes under Saline–Alkaline Stress

“…This new strategy of utilizing denitrifying bacteria to safely remediate secondary soil salinization holds significant implications, indicating its active role in the soil nitrogen cycle. This could be achieved by promoting nitrogen release or transformation, including biological processes such as nitrogen fixation and organic matter decomposition [32].…”