Gorczyca Anna, Kasprowicz Marek J, Lemek Tadeusz
a Department of Agricultural Environment Protection , University of Agriculture in Krakow , Krakow , Poland.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2014;49(6):741-52. doi: 10.1080/10934529.2014.867217.
The aim of the study was an in vitro evaluation of the effect of MWCNTs on the conidia of two strains of entomopathogenic fungus, Metarhizium anisopliae. The study made use of water suspensions of MWCNTs (concentration ∼ 3 mg·mL(-1)) made from commercial nanotubes and centrifuged. The conidia were placed in contact with nanotubes for 240 h. An assessment of MWCNT influence on conidia was performed after 1, 24, 72 and 240 h and focused on the linear growth of vegetative mycelium derived from these conidia, mycelium sporulation in subcultures and pathogenicity. Using TEM imaging, it was demonstrated that carbon nanotubes are able to damage cell membranes of the examined fungi conidia. However, the absence was noted of a significantly fungistatic effect of both MWCNT suspensions on the examined strains with respect to the physiological features in question. The increase in vegetative mycelium effected by spores after contact with MWCNTs was characterized by a slight modification in relation to the control. There was no strong trend (inhibition - stimulation), in relation to the effect of the tested suspension of carbon nanotubes, on the development of the vegetative mycelium in in vitro culture. Sporulation of the mycelium after completion of the culture only occurred in one case (strain Ma73F and culture of spores after 24-h contact with MWCNTs) significantly more intensely than in the controls. With respect to pathogenicity for test insects compared to the control strain, Ma73F spores grown from the longest contact with nanotubes suspensions performed significantly better. On the basis of the calculated of mycelium index growth rates and the time of death of the test insects (LT50), it was found that the adverse effects of water suspension MWCNTs on the spores of M. anisopliae were applied after a short contact with biological material. This indicates unfavorable physical rather than chemical effects on the tested cell. Over time, nanotube aggregation in water suspensions led to changes in their influence on the cells under examination.
本研究的目的是在体外评估多壁碳纳米管（MWCNTs）对两种昆虫病原真菌绿僵菌（Metarhizium anisopliae）菌株分生孢子的影响。该研究使用了由商业纳米管制成并经过离心处理的多壁碳纳米管水悬浮液（浓度约为3 mg·mL(-1)）。将分生孢子与纳米管接触240小时。在1、24、72和240小时后评估多壁碳纳米管对分生孢子的影响，重点关注源自这些分生孢子的营养菌丝体的线性生长、继代培养中菌丝体的孢子形成以及致病性。通过透射电子显微镜（TEM）成像表明，碳纳米管能够破坏所检测真菌分生孢子的细胞膜。然而，就所讨论的生理特征而言，未观察到两种多壁碳纳米管悬浮液对所检测菌株具有显著的抑菌作用。与对照相比，孢子与多壁碳纳米管接触后营养菌丝体的增加表现为略有改变。就碳纳米管测试悬浮液对体外培养中营养菌丝体发育的影响而言，没有明显的趋势（抑制 - 刺激）。培养结束后菌丝体的孢子形成仅在一种情况下（Ma73F菌株以及孢子与多壁碳纳米管接触24小时后的培养物）显著比对照更强烈。与对照菌株相比，对于测试昆虫的致病性，与纳米管悬浮液接触时间最长的Ma73F孢子表现明显更好。根据计算的菌丝体指数生长速率和测试昆虫的死亡时间（LT50），发现多壁碳纳米管水悬浮液与生物材料短时间接触后就会对绿僵菌的孢子产生不利影响。这表明对测试细胞产生不利影响的是物理作用而非化学作用。随着时间的推移，水悬浮液中的纳米管聚集导致其对所检测细胞的影响发生变化。
