Low-frequency ultrasound and nitrogen limitation induced enhancement in biomass production and lipid accumulation of Tetradesmus obliquus FACHB-12

Effects of Ultrasonic Stimulation and Light Intensity on the Growth Rate and Biomass Productivity of Chlorella ellipsoidea in a Closed-Batch Cultivation System

“…This phenomenon resembles findings in the batch cultivation of Squama quadricauda, where the highest biomass yield of 0.68 g/L/day was recorded at a light intensity of 42.86 μmol m −2 s −1 for 5 min. Similarly, Scenedesmus obliquus (FACHB12) displayed a biomass production of 0.69 g/L/day when cultured at 14.29 μmol m −2 s −1 after 3 min of sound wave stimulation at 23 Hz [25]. Based on the results, lower light intensity is optimal for accelerating the growth rate and biomass production of algae in this study.…”

Enhancing the growth of thermophilic Bacillus licheniformis YYC4 by low-intensity fixed-frequency continuous ultrasound

“…2 E, positive effect on biomass was achieved after ultrasonic treatment (<2 h). Sonicated sample (1.5 h) had the highest biomass, which was improved by 48.95%, compared with the other groups, implying that, a suitable ultrasonication time could enhance the contact of the strain with nutrients, thereby promoting growth of the strain [19] . The growth of B. licheniformis YYC4 was inhibited by 2.5 and 3.0 h of sonication, indicating that prolonged sonication caused negative effects on the cell growth, which might be attributed to the increasing cavitation impact or excessive permeability of the cell membrane [22] .…”

“…Also, Huang et al [7] showed that power density<160 W/L had positive effects on the growth of the probiotics in the process of seed culture, illustrating that microorganisms have different sensitivities to ultrasound treatment. It was reported that low-intensity ultrasound could effectively promote the growth of microorganism, while excessive sonication results in the reverse [19] . Therefore, 120 W was regarded as the optimum ultrasonic power to treat B. licheniformis YYC4.…”

The Influence of Ultrasound on the Growth of Nannochloris sp. in Modified Growth Medium

“…In order to overcome the opposite trends between biomass accumulation and lipid content, a two-stage cultivation strategy was proposed, consisting of initial optimal conditions for biomass accumulation, followed by lipid promoting cultivation in the presence of stress factors [ 12 ]. Wei et al successfully applied this two-stage strategy for the microalgae strain Tetradesmus obliquus , resulting in an increase of 32.1% for biomass production and 44.5% for lipid content, when nitrogen limitation and low-frequency ultrasonic treatment was applied [ 13 ].…”