Former chapter 11 trustee sought to recover expenses from secured creditor, relying on 11 U.S.C. § 506(c). The court held that only the current, chapter 7, trustee had standing to assert a § 506(c) claim, and that any recovery under that provision would belong to the estate, rather than the trustee. Former trustee's expenses must be recovered pursuant to 11 U.S.C. § 726(b).