Bioavailability of Organic Phosphorus Compounds to the Harmful Dinoflagellate Karenia mikimotoi

Abstract

Karenia mikimotoi is one of the most well-known harmful bloom species in temperate coastal waters. The present study investigated the characteristics of alkaline phosphatase (APase) and phosphodiesterase (PDEase) activities in hydrolysis of two phosphomonoesters (adenosine triphosphate (ATP) and ribulose 5-phosphate (R5P)) and a phosphodiester (cyclic adenosine monophosphate (cAMP)) in K. mikimotoi and compared its growth and physiological responses to the different forms of phosphorus substrates. K. mikimotoi produced comparable quantities of APase and PDEase to hydrolyze the organic phosphorus substrates, although hydrolysis of the phosphomonoesters was much faster than that of the phosphodiester. The growth of K. mikimotoi on organic phosphorus substrates was comparable to or better than that on inorganic phosphate. The difference in particulate organic nutrients (carbon, nitrogen, and phosphorus) and hemolytic activity supported different rates of hydrolysis-assimilation of the various organic phosphorus substrates by K. mikimotoi. The hemolytic activities of K. mikimotoi in the presence of organic phosphorus substrates were several times those in the presence of inorganic phosphate during the exponential phase. This suggested the potential important role of organic phosphorus in K. mikimotoi blooms.

A simple method for algal species discrimination in East China Sea, using multiple satellite imagery

“…Such differences could arise from the different cellular pigment contents of each species (Zapata, et al, 2012;Huang et al, 2021). The main accessory pigments are peridinin in P. donghaiense (peridinin/chl a ~ 0.824), and fucoxanthin (fucoxanthin/chl a 0.33-1.75) in K. mikimotoi.…”

Nutrient Flux under the Influence of Melt Water Runoff from Volcanic Territories and Ecosystem Response of Vilyuchinskaya and Avachinskaya Bays in Southeastern Kamchatka

“…According to the latest studies [14,15] and previous articles [62], dinoflagellates, including potentially toxic species, dominate in the case of a significant growth in DIN/DIP ratios. This is related to the capability of dinoflagellates to use different forms of P in their competition with diatoms [13,16]. The maximum values of nutrient flux from river runoff being registered in summer may partly explain the harmful blooms frequently observed in the study area over the last 50 years and normally occurring in August-October [38].…”

“…Nutrient flux in the river runoff in coastal basins is inseparably linked with such currently topical problems as eutrophication [1][2][3], phytoplankton bloom outbreaks, and red tide events [4][5][6][7], as well as hypoxia and anoxia [8][9][10]. Variation of the DIN/DIP ratio and increases in organic matter (OM) concentrations may be the main reason for dinoflagellate blooms, including their toxic species [11][12][13][14][15][16].…”

Photocatalytic formation of P–S bonds via CdSeS/CdZnS quantum dots under visible light irradiation

“…1 It finds extensive use in organic chemistry, [2][3][4][5][6] materials science, 7,8 biomedicine, and other fields. [9][10][11] In particular, the inclusion of the P-S or P(O)-S bond in organophosphorus compounds imparts distinctive physicochemical properties, structural characteristics, and biological activities. [12][13][14][15] As a result, thiophosphines (R 2 P-SR 1 ), phosphinothioates (R 2 P(O)-SR), phosphonodithioates (RP(O)-(SR 1 ) 2 ), and phosphorothioates (RO) 2 P(O)-SR 1 find wide applications in diverse fields.…”