Isao Maruyama

Application of unicellular algae Chlorella vulgaris for the mass-culture of marine rotifer Brachionus

Condensed suspension of Chlorellavulgaris was used for the food of the rotifer Brachionus plicatilis and B. rotundiformis inplace of Nannochloropsis oculata. Thisreport describes the characteristics of C. vulgaris as arotifer food in comparison with N. oculata and thepresent status of this field.The cell components of C. vulgarissuch as protein content, amino acids, minerals andvitamins are generally similar to those of N. oculata. However, the taxonomic status of thesealgal species are different. Based on thesimilarity of cell components, the dietary value ofC. vulgaris is equal in value to that of N. oculata for rotifer growth. Dietary value ofC. vulgaris can be improved by addition ofvitamin B12. This improved C. vulgaris is currently widely used as an indispensable food organism for rotifer culture. Recent investigationshave shown that the use of the condensed suspensionof C. vulgaris makes it possible tosignificantly increase the rotifer density atharvest. Application of condensed C. vulgaris has made rotifer culture quite easy because theculture of N. oculata is no longer required,and intensive rotifer production in aquaculture cannow be realized.

Effect of maternal Chlorella supplementation on carotenoid concentration in breast milk at early lactation

Abstract Breast milk carotenoids provide neonates with a source of vitamin A and potentially, oxidative stress protection and other health benefits. Chlorella, which has high levels of carotenoids such as lutein, zeaxanthin and β-carotene, is an effective dietary source of carotenoids for humans. In this study, the effect of maternal supplementation with Chlorella on carotenoid levels in breast milk at early lactation was investigated. Ten healthy, pregnant women received 6 g of Chlorella daily from gestational week 16–20 until the day of delivery (Chlorella group); ten others did not (control group). Among the carotenoids detected in breast milk, lutein, zeaxanthin and β-carotene concentrations in the Chlorella group were 2.6-fold (p = 0.001), 2.7-fold (p = 0.001) and 1.7-fold (p = 0.049) higher, respectively, than those in the control group. Our study shows that Chlorella intake during pregnancy is effective in improving the carotenoid status of breast milk at early lactation.

Effects of deep seawater on the growth of several species of marine micro-algae

Deep seawater (DSW; seawater under the euphotic layer), obtained from Deep Seawater Laboratory in Muroto, Japan, was applied to the culture ofDunaliella tertiolecta, D. salina, Nannochloropsis oculata, N. salina, Porphyridium cruentum, Tetraselmis tetrahele, andChaetoceros ceratosporum. DSW supported the exponential growth of every species. The growth yields were at 14.7 (±2.3 SD) mg dry weight per liter, and could be heightened by the addition of nitrate to DSW.

Parachlorella beyerinckii accelerates lead excretion in mice

The effect of Parachlorella beyerinckii CK-5, previously identified as Chlorella vulgaris, on gastrointestinal absorption of lead was investigated in mice. Female ICR mice aged 7 weeks were orally administered lead acetate solution at doses of 20 mg and 40 mg of lead per mouse, with or without 100 mg of P. beyerinckii powder (BP). The mice were bred for 24 hours. The amount of lead excreted in feces within 24 hours, and the lead levels of the blood, liver and kidney were analyzed by atomic absorption spectrometry. The percentage of total fecal excretion in mice administered BP increased by 27.7% in 20 mg lead administered mice and 17.2% in 40 mg lead administered mice in comparison to control mice, respectively. On the other hand, the lead levels of the blood, liver and kidney of BPadministered mice at 24 hours after lead administration were 48-63% lower as compared with those of control mice. The lead adsorption ability of BP and the pepsin non-digestive residue of BP (dBP) were investigated in vitro. One hundred mg of BP and dBP could adsorb 10.6 mg and 6.0 mg of lead in a 20 mg per 10 mL of lead solution, respectively. The lead absorption abilities of BP and dBP were considered to contribute to the prevention of gastrointestinal absorption of lead and the promotion of the excretion of lead. These results suggested that BP treatment might be useful in animals and humans exposed to lead.